Based on this question and other answers I would suggest the following rules:

1. Editing the own question once it has an answer should be subject to approval as editing someone else’s question.
2. Unaccepting an answer an answer once it was accepted should require an explanation and subject to approval.

Based on this question and other answers, I would suggest the following rules:

1. Editing one’s own question once it has an answer should be subject to approval, the same as editing someone else’s question.
2. Unaccepting an answer an answer once it was accepted should require an explanation and be subject to approval.