If I want to edit a question, is there any way to not let anyone else see the previous version?
No, the the idea of providing that edit history is to maintain total transparency about what is being done with a post.
There are limited cases where we may redact certain information that was posted inadvertently (e.g. highly-sensitive or personal information like a password), but you would need to 'flag' the post for moderator attention or use the 'contact us' link at the bottom of the site. Normally, we do not allow the hiding or removal of edit history.