In the name of simplification I made the next iteration of my choices. I decided to go back to the original idea of having the boring regular ACS style key switch... It's not as exciting as a push start, nor is it as neat as having lots of cool toggles to mess with... but in the end it will be an easy transition from my 172 to the RV-10... cause it's the same.
For batteries and alternator I'm sticking with a single main battery and the IBBS backup. The IBBS is independent of the VPX so if there's an issue with it then I'll at least have 1 G3X, EFIS, GTN650 and comms. Then if that all goes out then I have the G5... for my flying that's a good balance of safety and simplicity. I am going to go ahead and have the extra alternator as well. The charging system is actually something I've had go out in the 172... twice.
I removed a few other things as well, like the AP Power switch and the 2nd ADAHRS... The G5 if on the CAN bus can supply the G3Xs with that info, functioning as the backup.
So now I'm working on updating the schematic and might change it even more. I need to now figure out what to do with the pinky button.... Maybe an Airhorn?