Well it ain't quite that simple. Required BY LAW to have the switching system interlocked so that emergency power and grid power CAN NOT be accidently interconnected
Correct. You would need a Transfer Switch. I have Transfer Switch experience with RV's. The difference is as stated RV transfer switches are the same Amp capacity as the Shore line (power in). Something different would be needed to use a smaller generator than one with 200 Amp main panel.