Why did my post get deleted?
So many possible reasons - the biggest ones are...
1) Wrong Forum
Check that it did actually get deleted and not just moved to a more appropriate forum. Remember, posting Wanted ads, Gig ads, Wishlist requests, etc in the main forum will be moved. There are dedicated parts of the site for that info already. Only if there is special cause for the post will it stay there, so if you post and it vanishes, check the other forums and don't make another post complaining about the absence of the first one!
Making posts that just blindly offend or have nothing to do with anything will often just get binned. Moderators already have enough work dealing with legitimate conversation and don't need to waste time with threads that have no place on a music community site. There's a lot of tolerance for non-music posts that might have common interest with the other users, but not posts that have no intent or point. Keep your posts civil and rational and they'll most likely stay.
more may follow...