If I were to post another artist's work in this thread:
without telling them, could that end up being a 'legal matter'?
(say, the artist sees his work in the thread and doesn't want it there, could my account be banned?)
To answer your question, for the most part no. Unless you're doing it to spite the artist or drag up drama, if you post a link (without claiming the art as your own of course) you won't get banned.
If the artist doesn't want it posted he can PM one of the admins or mods to just have the link removed.
Do I get banned for asking silly questions in order to boost my initial post count, so that my serious posts in the feedback/critique section gets released from the "moderation"? A couple of posts have been in limbo for a day, I didn't realize how hard it was to prove that I am not a bot.
Asking silly questions will make the mods keep an eye on you. Posting art is the best thing you can do.
If your links are to a company website completely unrelated to art, and the only reason you made your account is to spread those links, that is spam and is typically a ban-worthy offense.
Well, if you're an idiot like mia23 and have a signature to a seo web design company. it's going to be pretty automatic.
Something about MIA's comments made me think "oh look, another spammer" even in the ones without sig links. I found it pretty funny that a spammer would basically ask if spamming was against the rules. It's like they've just been sitting around this whole time wondering why they keep getting banned, and it just finally occurred to them.