First of all, dear anon, thank you for taking the time to leave a comment! I'm also really glad to hear Tomoyo's post wasn't too tl;dr to be off-putting, as that was a very real concern of mine while writing it.
Second, I think I have to agree with you, for the most part. I think I mentioned it in a past HMD that I was having trouble and feeling unsure with Hisui, and unfortunately, that is still the case. Weird as it may sound, I'm actually glad you brought that up, because that means I'm not just imagining it. I think a part of the "genericness" with her might come from the fact that I try to balance her general strangeness with her more nice, angel-y side, and sometimes that does result in what you call generically nice responses. But I have to think about what to do with that, and I'll certainly try to pay it more attention in the future!
As for Subaru, in part, I do agree that he can come across as fairly generic, too; but as for the stiltedness as you mentioned, I've kept his responses short lately, but for a reason. He isn't a talkative person on a good day, and frankly, those have been far and few between with all the drama that's been going on with the four. So, talk as he might with people to not be a social recluse, he doesn't actually... really want to talk with people all that much right now. Where he might ask questions or something like that on his normal days, right now, he's even more reserved than usual, and even if he doesn't realize it himself, he just can't bring himself to be as interested or invested in other people's business as he would usually be (unless, of course, they're people he's close to, like X!Kamui, Sakura or Hokuto, for example).
I'm not trying to say that explains it away, of course, so please don't take it that way. I'm just trying to explain to you that his short responses, at least in part, have been a conscious decision, but I'm sorry if some of his threads have come across as generic. Short responses are no excuse for boring responses, after all, and I promise to work on it to make them not so!
Whoa, this is a really tl;dr response, but as it's me who's answering you, perhaps it ought not to be a surprise. Anyway, thank you times a hundred for leaving crit, I'm always so glad to get it. ♥