Is there a way I could chnage my username? If i do, will my old posts show up with the new name or not?
There used to be a ticket option for it but since it's no longer there I assume they aren't doing anymore name changes for the time being. Even if you could change your user name, any old post where someone quotes you would still show up on a Google search. Hell, even if you changed your user name and then got your account deleted, there would still be evidence of your membership here in Google search results. There is pretty much no way to change that now. And if that's what you're trying to do, then man... you have probably half a dozen other marijuana related sites that come up in a search for your name.