There is one Quoran who upvotes just about everything I write (or at least, did the first few months I was here). He’s one of the few Quorans I knew online pre-Quora. I appreciate it: I regard him as my Quora sponsor.
There are Quorans I consider close Quora-friends, and I upvote most of their stuff I see in my feed, as a mark of group loyalty. Not all of it; if it was unspectacular, or trollish, or something I both disagree with and think was not well argued, I’ll decline to upvote. And hope they don’t notice. I don’t want to upvote automatically, but I will upvote by default.
In both cases, these are people I’ve gotten to know already. If some random starts upvoting me lots, well, I’ll make a point of getting to know them; but if we have that kind of overlapping interests, my experience until now has been that I already have gotten to know them.
As for comments: no, I cherish comments. If anything, I am the one creeping out other people with comments. Some people make it clear that they appreciate the banter, and reciprocate. Some people make it clear that they don’t; well, their loss.