My OFU (Homestuck) is still very much in the planning stages. In fact, up until I saw this post I'd kinda forgotten that I'd need to have a coordinator. Oops.

So, it's Miss Carol, which is a name I totally pulled out of thin air, but which will do fine and I actually rather like.

Actions: She would spend some time looking at the tapestries, but if there's any food available she would be going back to get more quite often. She'll be a bit skeptical to the news at first, but ready to cooperate. Towards the end she'll probably get antsy, wanting to go organize defensive measures for her OFU.

Speech: "If the threat is as serious as you say then something must be done. What are we going to do about it, and what can OFUH do to help?"

I'll give you stuff for all four and you can mix and match and pick and choose to your liking.

IAHF
Mr Hugh
1) Sitting there a bit awkwardly, probably, looking wistfully at any leftovers from any earlier dinners and then deciding probably not to eat them (he might not trust the food).
2) A certain air of resigned determination if this is post-IAHF; he'd be all "we've dealt with that before; we'll be fine", but a bit more formally? He'll offer to send help to OFUDisc.

Mr Allen
1) Not sure what he's doing in Meduseld, but nonetheless wide-eyed at the carvings and tapestries and stuff.
2) "Let them try." He'll try to be machismo about it but it will probably fail because he will be worried and probably likely to phone up the entire damn staff once he gets somewhere that supports communications (Middle-earth ain't got wifi, duh). He may also extend an offer to help OFUDisc.

MBSFA

Mr Ben
1) Interestedly touching the tapestries or something.
2) A bit of shock, a bit of worry, but he'll keep it together until he gets back and then he'll have a bit of a meltdown until someone from the staff coaxes it out of him (Ella the therapist?). I don't think MBSFA will get involved with the attack on OFUDisc because their resources aren't that big; they're just a subcampus of the BSFA.

Mr Marty
1) Disinterested, and probably a bit annoyed too. Sitting by the fire and possibly shivering a little.
2) He'll probably curse a lot and then rush off to increase security back home.

The Coordinator for OfWho (Miss Kat) is a rather taciturn woman who loves to fidget with random objects that she either has in her pockets or finds around her, so you might not have to write a whole lot of dialogue.
"I must inform the minis to double the defenses, we cannot have another security breach."
Hope this helps!