MyG37 - 2011 Infiniti G37x driver's power seat + passenger windows issue

Hey guys! I would like to know if you guys are able to diagnose my problem. I had an appointment with Nissan yesterday but they couldn't diagnose the problem and are telling me that they need $600 for them to do a deep 3-hour electrical diagnostic... I'm not paying $600 for a diagnostic. I have a 2011 Infiniti G37x and yesterday morning all my windows stopped working except for the driver’s window. I can also not lock the doors via the door lock button. For a week I have been having a problem where the windows would not function for a few seconds after the car had been turned on, but now it has progressed to a permanent nonfunctional state. Around 3 days ago the driver’s power seat also stopped working. I don’t know what it could be. I replaced the battery and checked the fuses. I’m thinking that it could be the BCM but I don’t know. I would like to know what you guys think it could be, what you guys think I should do to diagnose exactly what's wrong, and what could be an easy temporary fix for me to at least get my windows up until I permanently fix the issue. If you can provide any help, I will greatly appreciate it!