Both of the boats we've owned have had surge brakes on the trailer so no power is needed to release the brakes. Both trailers have bulbs and even though they both claimed to be waterproof, I've always pulled the plug before backing down the ramp. An ounce of prevention and all that stuff.....
As for spousal comedy at the ramp, we try not to provide any! We've got our launch/retrieval procedures down to a science. Launching or retrieving, she's on the boat and I'm on the ground, moving our stuff between the boat and truck, AWAY from the ramp. Since we launch at WAM, I drive the truck, she handles the lines on the boat, pulling it off the trailer or pulling it on. When retrieving, I'm in the water winching it up. Piece of cake!