how do you delete questions???
You can't delete questions (or else we wouldn't have very many!)
Advisors cannot delete them for you either.
Only thedude can delete them, you can funmail him if you have a good reason for deletion.
You can however set your questions to "anonymous" . Go to your profile and click "view all" under your recent questions. Then you should be able to "mark as anonymous".
I don't think you can delete them yourself, I think you have to ask one of the advisors to do it for you.