I'm very easily distracted so I use Leechblock with Firefox to help me focus while I'm at work. This works great (especially because I have it set to require a 64-character password in order to make any changes to the settings). I have one profile for "personal" stuff where only a few sites (e.g. Pandora) are always allowed and everything else is only unblocked for a few minutes each hour (I give myself those few minutes each hour to take a break, check facebook or personal email, etc.). In the "work" profile, all distracting sites are blocked. I'm pretty good about actively blocking new sites that I get to that are not work-related.
Unfortunately I've now grown accustomed to just creating a new Firefox profile whenever I want to go to a page that's blocked in both profiles. It's too easy to start with the profile manager, and when Firefox starts with the new profile, of course there are no extensions so every site is available.
Is there any way to remove the ability to add a new profile or start the profile manager (or at least make it reasonably difficult to do so)?