If I were you, I'd check every single fuse just in case. As for the windows, it could be the motor that's bad, since the window motor is known to break down for the G. But here are some links that you might be able to use.
http://www.nicoclub.com/FSM/G35/Coupe/h ... hinfo.com/
you mentioned that the radio/navi was stolen? Instead of replacing with OEM, you should get the JDM double-din finisher and get an aftermarket headunit since OEM Bose headunit sucks anyways.