None, I always read them as soon as I see them. I think interacting with other people on site is what makes it fun and interesting, like it's the whole point of sites like this.
None. I usually try to read them all. I'll respond to it if I think a response is appropriate. If I dont know how to respond, I'll upvote the comment and move on. If it's a troll comment, I don't give them anything. Validating trolls is a waste of time. XD
Yeah, sometimes someone will make a good comment on my post, or make a positive reply to one of my comments, and I won't comment back simply because I have nothing further to say. So I just leave it, but then I feel a little guilty for ignoring them, lol.