a) Anyone can edit the Wiki, so yes, you're allowed to. However, I'd also point out that it isn't necessary to make an article for every badfic, no matter how horrendous. There will always be more, and the Wiki is for PPC stuff, not badfic. So, badfics should either be related to missions or particularly notorious. Also, make sure you follow the formatting of the Wiki.

b) Links to other articles are formed like this: [[Name of Article]] or this: [[Name of Article|text]]

b.1) External links go like this: [URL.tag] or this: [URL.tag Text]

c) I think the spoiler warning tag is: {{spoiler}} I'd check that by looking at the Wiki markup for pages with the warning on it. You do that by clicking "edit this page" or whatever it says.

~Neshomeh

Okay. I'll calm down. But I'm normally that crazy--I used to be one of the badfic authors(I keep one of them on my ff.net account*shudders*)
Okay. The Link. *neon sign that says "Links of Doom" pops up* For the first one -- http://esteliel.de/cgi-bin/1/story.pl?next=1&chapter=0 -- That brings you to the first chapter, and completely avoids the attempt to rationalize destroying Tolkien's canon with this story. Did I mention that they won't delete chapters, and that their are multiple oppotunities on some threads to write a PPC mission for this...?
*There's another one.* It could be even worse than the first one. http://www.esteliel.de/cgi-bin/3/story.pl?next=1&chapter=0 It's a War of the Ring interactive...horror, shall we say? The link is for the first chapter, and the results of it can be just as horrifying. There are, at last count thankfully only 316 chapters of brainmelting horror--although some of them are pretty good with the coherency and an attempt for plots...
If you like Denethor or Thranduil, or pretty much any of the canon characters, don't read unless you've got an entire case of Bleepka to yourself.
--The horror-
Honu_Wahine