You can undo changes by going into the Changes tab of the profile, click on the change you want to undo, and click on the restore data as it was link.
You can remove someone from the Trusted List by going into the Privacy tab of the profile and removing them.
Note, however, that if the profiles are Open profiles, anyone can make changes to the profiles whether or not they are on the Trusted List, so removing them from the Trusted List will only prevent them from making changes if the profiles are Private or Public profiles (as determined by their privacy settings).