Always on the front on ones I have seen, mostly Dometic
Right or left does not matter as the 3-wires from AC will be kind-of looped anyway and hang in the return air space/cavity. The side that the power is attached will likely be where the knobs are located. If middle then middle, if knobs on the right then route the power there.
If you can come from the front then should be perfect, if from the side then, yes, aim at the front 5 inches.
When you say,Romex, do you mean solid copper house wire?
Generally RVers tend to believe that solid wire will be more likely to develop cracks, but the wound/stranded electrical cord (like a heavy extension cord) will not crack due to vibrations on the road.
I always buy a heavy gauge extension cord (cheaper than buying by the foot) and use that for the AC electrical. Im on 6th camper renno.
