Charles, you are right, there are more experts over in the tech forum.
I,m not an expert, but can give a little insight!
1. I don't think you have to use a coleman digital, but it might make the wire swap more understandable.
2. I'd say you just need to match the wire colors.
3. Yes, you would need 50 amp hookup, to run both ACs at the same time, due to the fact you will have other draw as well. The converter, fridge, micro, elec WH, etc.
4. Mine is Dometic, works well with my Dometic AC.
I don't think you would want to turn that front AC around, and controls could not be turned to the foot end.
Be sure to turn that fantastic fan off before flushing. It will pull air right out of the black tank!! Lol
Jerry