Well, since they're aliens, psychics could be, well, just psychic. Since you've admitted you're already probably not going to be technical about this, you might be able to just make some things, like why aliens have psychic powers, pass. Not everything has to be explained. Some people forget that.
Okay, now my rundown on these species, one by one, as well as a few of my ideas on what you might do with them.
Human: The idea of humans as a "jack-of-all-trades" species has been used so many times that the concept is pretty stale. However, if there was some reasoning behind why they had been involved in so many fields, it could set up a history, round them out, and make them fit better into the scheme of things.
A lot of people use the "humans are in charge" format to accomplish this, saying that the humans are in so many places because they run the show, but Id go against using that concept, since putting humans in a distant galaxy is basically self-inserting an entire species already and making them in charge when there are several other species who'd be more suited to the role never made sense to me. I'd recommend something in particular, but since I don't know the history behind this universe, I can't really do that.
Roon: The space elf concept is also rather overused, though I like that this universe sees their space elves as the stuck-up twits they tend to be. That could actually be a relatively good springboard for inter-species conflict, since the space elves are, as ever, racist and obnoxious, and for once, the others aren't going to be putting up with their crap. Actually, they might be a better choice for being the Mortu's psychotic slavemasters, since they wouldn't see the oppression of another sapient race as a problem and might just as easily view every other species as nothing more than animals. There could be interesting plot hooks for ideological conflict there.
Trull: I'm seeing a disconnect between being mechanically-inclined and erudite while still lacking mental skill and imagination. Typically, in order to be skilled with machines and other fields of study, one requires some extent of imagination to do so. However, the idea could be taken in a few interesting directions if set up, and I've got two ideas that might be a basis for set-ups.
Idea one: they project the idea of being self-contained and generally unintelligent to hide their true activities, which involve the intense study and mechanical work. Why? I don't know, since this universe's history isn't too familiar to me. Perhaps they have a traditional dislike of outsiders getting involved in their projects, and their expansion into space has made them paranoid of other species meddling with their work. Perhaps they're planning something and don't want anyone else to know what they're up to. Or maybe they just don't like to be pestered, and spreading the idea that they're stupid would make people leave them alone.
Idea two: most of their race is just as unimaginative as suggested, and as such, they are ruled over by a small group of mutant members of their race who possess higher intelligence and mechanical ability. This is a less original idea, but it also has potential, I think. Maybe the mutant leaders could be tied into the propensity of this universe for psychic power, or exhibit traits of psychic abilities themselves. Maybe they're a remnant of a precursor race's failed uplift experiment. Possibilities.
Tokkar: There's not really a lot of information here, but still a few interesting concepts. If they hardly leave their home planet, how did they get well-known for their psychic abilities? How does the rest of the galactic community feel about them and their supernatural powers? And exactly what can their psychic powers accomplish? Telepathy, telekinesis, electrokinesis, teleportation, what? Setting what is possible for a species-wide power set is important, and since these guys appear to be one of the few here that are naturally psychic, they would need to be especially certain of what they are capable of doing.
Amphibe: There's not really much to say about these guys, except for two questions I have How do they stay moist, and what happens if they start to get dry? I'd imagine they might carry around some sort of fluid packs to keep themselves within a recommended moisture range when off-world, but it might need to be a full-body soak. And once they get dry, does their blood start to clot up, do they get slower and weaker, or less intelligent, or something else? If something bad will happen to their race if they're left out in the sun, it's important to establish what it is or at least how bad it is. If it's just the alien equivalent of chapped lips, the stakes are much lower than if it sends them into a coma.
Lepida: This starts to bring up a recurring question I have: Is this what these races call themselves? I mean, if the humans couldn't understand a Lepida's wacky bug-language or a Mossian's plant-pronunciations, and the names were given by humans, that's one thing, but if the aliens name for themselves is a modified term from World One, and that World One-based naming is consistent among multiple races, that's a no-go unless there's a really good reason as to why, and I mean a really good reason.
Also, I agree with what firemagic said earlier about species-wide cultures being a bad thing. One trait being ubiquitous among a race isn't bad, especially if it's something that's a deeply ingrained personality characteristic like their level of aggressiveness or their social ability, but having political views and love of art and the like be universal across an entire species is pretty implausible. Even if it started out like that, differences would start to rise after a few decades/centuries/millennia(I don't know how long your races tend to live) passed and the new generation realized they didn't like to spend their whole day looking at paintings.
One more: What do humanoid moths look like? Are they similar to humans, but with feathery antennae and moth-wings coming out of their backs? Because they would not be able to fly with those, unless the wings were so big they couldn't fit them through human-built doors. Moth wings are fragile and not terribly efficient for a spacefaring race. At least some species could fold them up and protect them behind wing cases or something. Moth wings would just be an encumbrance.
Sectoid: These guys don't really have a lot of description here, and while I like the idea of a knight in shining chitin, they might be better if their cultural idea was merged with the one currently used by the Saurians. Again, just a suggestion, like all of my previous ideas have been, but it could work well. I'll go into detail about that in the Saurian section.
Saurian: Okay, the space elves could be taken in an interesting direction, but lizard-man space pirates that are low in intelligence just invoke a half-dozen clichés that I'm not sure the race could recover from. It doesn't help that their species name is a World One term for a monophylum of reptiles.
Their cultural description was pretty good, though, though I may be biased because when you mentioned efficiency and industry I got a mental image of scenes from Great Depression-era silent movies about factories being played out by lizard people.
Now, the Sectoid bit. You said earlier that the Sectoids tended to be chivalrous and honorable, but what if, instead of just an inborn trait, it was them compensating for the rest of their race? When you mentioned the Saurian race's love of self-improvement, my first thought was of... well, to be fair, I my first thought was of cyborgs, but my second thought was of the potential for cultural conflict that could cause. For them, the lizard-space-pirates, that wouldn't go very far, but if you transplant it to the Sectoids, it starts getting interesting. Possibly there was a series of wars in the past, with their species fighting over concept shifts or possible changes in intra-species affairs, and the losing faction was exiled from the planet. The chivalrous Sectoids wouldn't want to execute their own species, but the losing faction would still be harboring resentment for having lost the war.
After a few conflicts, they would have a large force of exiled dissidents, and while the on-world Sectoids would be as nice and proper as could be in an attempt to make a good impression on the rest of the galactic community, the off-world Sectoids could show even greater shifts and become generally hostile. It would be a nice twist on the typical sci-fi cultural monolith.
Also, if several exile factions were united by a Sectoid warlord, that could make an interesting early-stage conflict. And then maybe the un-united exiles could become the space pirates instead!
Okay, I got a little carried away there, but I like that idea and I might use a variation on it myself. Plus, physically altered sapient cicadas as space pirates. I love that.
Hexxion: Again, not much here, but I like how physically different these guys are. Everyone else is some sort of Intelligent Gerbil, to invoke a TVTropes title, but the Hexxoins are distinctly alien in comparison. Also, that description of their culture is vague enough that it might be able to work as how a species would actually behave, so that's a definite plus.
Ferrar: These guys... need work. The lion-like species being the "noble and proud" species is a cliché as it is, and while I like the sexual dimorphism, most of the rest of them looks like it could easily create potential problems, especially since the description of their culture is another one-personality-for-a-whole-species issue like the Lepidas had.
Mossian: Again, is this what they call themselves? That's actually vaguely insulting for a tree-based being, being compared to non-vascular plants. It'd be like comparing a human to an armadillo or a sloth or something. It doesn't seem like a direct insult, but it would probably make people mad.
They don't really have a lot of details either, but I'm not sure how a slow-moving and slow-reacting species became space-faring. It'd be like seeing Ents on the Enterprise. (The pun was not intended, but I like it now that I see it. It's just so corny.) Are they confined to a single world, like the Tokkar were?
Phylum: These guys need a different name for the same reason the Saurians would have: it is a taxonomic term and makes no sense as a species name. That being said, I like the idea of bright-colored jellyfish walking around in robot exo-suits, and they didn't have a one-personality culture, so they get an approval otherwise. How do the other races react to them, though? Do the Sectoids ever get offended that they refuse to show their faces? Do the Amphibe bond with them over their mutual need for environmental technology to survive off-world? There's possibility for good inter-species dynamics here.
Tenguri: These guys are... well, to put it bluntly, made almost entirely of clichés if that was a good summary of their culture. Castes in a Proud Warrior Race society, said Proud Warrior Race following pre-set laws of what constitutes their honor, bird people being anti-social, and it goes on. I like how they aren't a cultural monolith, though, so they could still be usable if they were rounded out more.
Kujaka: I really like their name, but I have no idea what a peacock-taur is intended to be. Are they half-peacock, half-bull? What does that even look like? I'm imagining feathered cows with beaks, and that is actually fairly off-putting. One-personality culture, again so I don't have a lot to say here other than asking what a species made of two races that have no manipulatory appendages could be a Proud Merchant Race. Do they have tentacles or something in addition to hooves and feathers?
Yagitsu: Not much variance here. I find it difficult to believe that an entire species would take to the shamanistic or nomadic lifestyle, though I can imagine a cultural majority perhaps, with a few splinter groups that embrace the possibilities of galactic society. Also, if they are so isolationist and decentralized, how were they introduced to the galactic community? It doesn't seem like something a species based around living only with "the essentials" would be interested in.
The theocracy idea could be interesting, but again, I'm biased because I like the idea of religious fanatic sheep flying spaceships.
Charchadon: I like the Charchadon. I don't know why, since they seem almost as monolithic as some of the other races were. Maybe it's just the freshness of seeing land sharks in a space-based setting. Also, their name is fun to say. The superstitious and brutal nature of their culture could provide interesting story possibilities, especially if you go the full length and make them a less-than-enlightened race, living separated from the rest of the galaxy due to some turmoil or perhaps never having been introduced to the galactic community.
Perhaps this could bring them in with the more powerful psychic species as their battle-allies. I can see them teaming up with the Andomedians, with each providing a foil for the other's characteristics and rounding them both out, and the Charchodons could act as the hands and eyes of the Andromedians in the galaxy at large, since mysterious energy beings tend not to like interacting with others, and may have taken advantage of the Charchodons' low intelligence and superstitious nature to hold themselves up as gods.
