1) Can I recruit for work here?
No, sorry. Actively looking for work is restricted to the Classifieds part of the website. Posts that are looking for work will be edited and locked by a mod as soon as they see it. This (and the other pinned forum rules post) are your warning. NOTE: This includes looking for music placements. Take all of these kinds of posts to the Classifieds section.
2) Can I post my audio for feedback?
You bet! It seems that Youtube and Soundcloud generally work best and get a decent amount plays. Try to avoid services which force users to download files/etc or make you sign up to get access to the files. This tends to get fewer plays. When possible, give us an idea of what the audio was created for (i.e. RPG, puzzle game, iOS, XBLA etc). This helps us give proper feedback.
3) Can I post other's audio for discussion?
Yes, as long as you're clear that it's not your stuff. For example, if you want to discuss the awesome sound design in the latest God of War trailer, go for it! But give credit to where credit is due.
4) Can I post multiple topics at once?
Maybe... it depends on the content. If you're truly hosting several individual discussions at once, then I don't have a problem with it. If each topic is simply a variation of "look at me!!!" posts, then I'll probably close and delete the duplicates. Let's all share the board please.
5) Can I bump my topic?
Bumping happens less in the Music and Sound forum than in other spots. So I'm going to say go ahead and use your best judgement. It's probably not the best idea to bump it daily for five days straight. That will just annoy people and give you negative attention. If someone starts to get out of hand, I'll send off a warning message.
6) Can I post about something other than Music and Sound?
Probably not. There's other spots on GD.net which allow for more general discussion and such so post it there! Let's stick to all things audio here!