> The general pattern: SU has a problem with newbie biting.

All the issues you mentioned are not specific to newbies. I've been asking ~500 questions over 9 years on SU and there is a clear pattern of negativity around here. Negativity deters positive users from sticking around, while negative users remain, so that's the vicious cycle. Being more accountable for VTC/downvotes/unkind comments could be one solution, but obviously the clique of negative users always militate for the right to VTC/downvote/comment whatever they want. 

E.g. look at https://superuser.com/users?tab=Voters&filter=all and you'll see that the top 2 most active voters have  many more downvotes than upvotes (the #1 most active voter has almost 10 times more downvotes than upvotes!). Doesn't sound that positive to me.