On the hot and cold water issue, check that the by- pass valve set up for winterizing has been put back the right way around.
On the electric hot water, you can control the on/off from inside with the circuit breaker for the HW. Actually, with ours it shared with the microwave so it had a three way MW/off/HW switch.
The HW was plugged onto a wall receptacle that went to that switch and the circuit breaker. If you don't want to use the circuit breaker as a switch, just un-plug and plug in. Or else use a power bar that has its own switch that might come out where you can reach it better.