Without the electic fans, stock alternator will be fine. If the car will be idling in traffic or used for putt putt parade stuff with any combo of lights, heater fan, and wipers on - that's when a little better output at idle speed is nice.
OK. Do you want to eliminate all or some of the toggle switches and use the ignition switch?
Depends on the wiring strategy. So far, it seems like the previous owner knew what he was doing. If you want to do it more neatly, you could have a little distribution box on the inner fender.
Got it. Its a dead end now.