I already posted approximately fifty questions on Stack Overflow. Some were useful for me, but are completely useless to Stack Overflow members and do not bring new users to the website. I can put as example a question or another one where I asked something by mistake. Since there are few chances that somebody will do the same mistake, the question has no reason to survive.
Is it a good idea for every user to "clean" his/her profile by removing questions which prove to be useless to other Stack Overflow members?
What will happen to the reputation of an author of an accepted answer? Of course, removing an answered question is not a solution if it decreases the reputation of people who took their time to answer.
When you delete a question, all the associated reputation disappears.
Do Not Delete Valid Content
The reason is that someone else may have experienced the same problem you have. So Isn’t it too fast for an ASP.NET page to download in 0 ms? is actually a valid question, because someone else may have the same question, and in fact people were able to generate coherent and useful answers for you.
If people were able to give you useful answers that got upvotes, then you should leave the question up.
The only case when you should delete a question is if it "closable".
... and other such reasons.
If your question has generated no meaningful responses, you don't need the answer, and you don't think anyone else could possibly have the same question, you might want to delete.
But if the question is well-formed and valid, there is no harm in leaving it up.
What will happen to the reputation of an author of an accepted answer?
Since this has so far not been answered - you can't delete a question with an accepted answer. From the FAQ:
You can't delete your own question if it:
- has an answer with upvotes (even if that answer has a net zero or negative score)
- has an accepted answer
- has multiple answers (even if there are no upvotes)
- has an answer with an awarded bounty
So the answer to your question is: Nothing happens to that user's reputation. Well, as the OP you could still unaccept the answer (-15 for the answerer, -2 for you) and then delete your question (if it was the only answer and had a score of 0). In this case, the author of the answer loses all the reputation they gained with it beforehand. (If you accepted your own answer, no reputation was involved to begin with.)