I don't think everyone does. but i also don't think completing VADA for a fight is proof someone never took peds their entire careers. Not saying either of these guys did but there are definitely people gaming the testing protocols and frequently skirting the line.
Taking gear and them quitting for an extended period of time would have no benefit. It would actually hurt you, as your test levels drop below normal.
Yup. Your baseline would drop and it would be easy to mess it up on the second go and get your cycle wrong. Anyway, innocent until proven guilty.