The idea of probationary/Lite permission groups for admins and moderators sounds like a great suggestion. If someone does end up donating just to make a big mess of everything, limiting their access to commands for an allotted time period will minimise the damage that needs to be fixed. I'm sure you guys got sick loading backups and such because I broke something on the server by accident. I don't think you guys need a bunch more admins doing that for you as well. Especially on purpose. :P
Something along those lines would work. I suppose we could set admins to watch these new admins/mods as well (sort of like, lets say, a probationary officer), but that'd be a little excessive. :L