Questions and other posts are not removed when your account is deleted [unless they score less than 0](https://meta.stackexchange.com/questions/5221/how-does-deleting-work-what-can-cause-a-post-to-be-deleted-and-what-does-that/5222#5222).

Questions may be deleted by the Original Poster before upvoted answers are posted.  
Once a Question has upvoted answers it's generally considered Community Property (per the license linked at the bottom of every page). So it can't be deleted.

Under unusual circumstance we can delete whole questions or redact parts thereof.