I feel I am a creative electrical wizard when it comes to making things work both 12 and 110 volt, but I decided to use the KISS theory in my bus. My entire bus runs off of one 15 amp circuit. That circuit enters the bus through a GFI, then branches out to a series of plain 110 volt light switches that control the individual circuits ie: fridge, outlets, aux, and lights. I have a male plug that feeds power to the bus, and three electrical outlets that i can tap into: Shore power, Inverter, Generator. I have to manually move the plug from one outlet to another when switching power sources, but this ensures that i won't fry my inverter, or generator by accidentally plugging one into the other.
My electrical system is cheap, simple, and reliable.
Quis custodiet ipsos custodes (who will watch the watchmen?)