Hey, welcome to the forums. With your new user account, you'll be able to use the coveted "Search" feature! So that's kind of cool. You can download your Factory Service Manual (FSM) to help you diagnose and work on your car.
http://www.nicoclub.com/archives/use-ni ... abase.html
Did some coolant/ water spray into your fuse and relay box in the engine bay maybe? The stuff that is not working is a lot of accessory type stuff. A lot of Nissans have Accessory 1 and Accessory 2 wiring systems. As a starting point, you will want to check the fuses and relays for those. I don't know your specific car, but maybe look at the fuses in the kick panel inside the car and then look at the fuses and relays in the box under the hood. (the fsm will help you locate these items). Your ignition switch (key) is related to those and could be going bad, but you would have had different clues like the car not starting randomly or the lights going on and off in the dash, wiggle the keys and it fixes itself, etc. I suspect the stuff in the box under the hood, due to your fender bender. If you do find a bad component, look at the wires behind it and make sure they aren't exposed or covered in coolant/ water and creating a short.