First place to look is for are tight clean battery cable connections. Make sure that the battery is fully charged. A marginal; battery will/can make your engine run ratty too, do you have your engine grounded to the fire wall of the car. The engine must be grounded to the body have seen lack of grounds do mysterious things.
As for your key switch returning Spray some spray like spray silicone lube on the key and then put it into the switch and turn back and forth.