I just want to know how does the site want to approach self destructive users?
A self destructive user in this context is a user who has contributed to the site and now wishes to delete their question or vandalize it.
Should anything be done?
Having a half-arsed undergraduate-level question on the site is bad, but having a vandalised post containing a random string of characters is worse. As such, I do not think we should tolerate self-vandalism, and we should insist the people deal with posts they want rid of through legitimate means (flagging, voting, etc.).
My suggestion would be to do the following: