what i think, for now at least:
1. my reasons have changed. when i first started posting writing to litkicks, it was because i hadn't written anything in a creative vein for a long time and i just wanted to see if i could write something that was interesting to someone other than me. as time has passed, i think i put things out here because i want to gauge the success of something. i'm a pretty terrible judge of my own work, and it helps me understand what i say a little better. so i guess, yeah... i do want feedback.
2. celebrate me, baby. praise me like you should. heh. seriously, i'm not going to turn down praise if it's offered (even though sometimes i've felt like i totally didn't deserve it). i mostly like when someone tells me what about a story works, or what could use some tightening. i like to discuss things. i'd love to ask writers why they chose to say things the way they did, and i'd do that if i thought it would turn into a good discussion of the work. i'd love for people to ask me things. i think it's a good way of learning.
3. not too many. i'm really bad about it. i decide i'm going to get better and i'll do a lot of replying in one or two days, then i'll stop. i need to work on that. basically, the type of reply i give depends on who posted. if i don't know someone very well, i might just say, "hey i liked that" (i do that a lot). but sometimes, when i know someone better and know what kind of reply that person generally seeks, i do my best to give that person the type of reply they'll find helpful.
4. yes. i kind of already answered this, but i often don't know what to say. that usually breaks down to me lurking in the shadows, instead of replying. sometimes i can't reply because i've read something that i just have nothing to add to. that could be because it's so damn good i don't want to touch it with my clumsy replies, or because it didn't really strike a chord with me and i'm not sure what to say.
5. i've never done the whole (pc) thing. i don't know why. i love feedback, and so that's probably just one of my quirks that i'll have to figure out at some point. most of the things that i post and want to hear from other people about go on the stories board... i think that place is pretty well suited to discussion of individual works, though it does often get incredibly silent, and then i'll post a story and seven people will post on top of it that day. it's a strange phenomenon, and i haven't quite figured out how the traffic works in there.
6. so many reasons, depending on the person or what they're replying/not replying to. for me, i could be speechless in a good way, speechless in a bad way, unsure of what type of reply the writer would like, or what type of thing i want to say, or... yeah. lots of reasons.