We towed a 2004 Tracker for 9 years and over 50,000 miles and loved it. If you are going to use separate bulbs for lights, where are you going to mount them?? There is no room in the tail light fixtures to add an additional bulb. I had wanted to go that route also, but had to use the diodes since there was no room for an additional bulb.
Regarding the key and the ignition. If you turn the engine off and move the key to the full off position, our Tracker did not lock the steering wheel unless you removed the key. So we always left the key in the "locked off" position with the key still in the ignition.
Ed Headington