I don't much about the car, a buddy called me about his son-in-law's car won't shut off when the key is turned off...After messing with it, it finally shut off, but it ran his batt. dead when he tried to start it back up after work...Looking for the experts...Could it be the ignition switch sticking?

Switch yes. Defective, but I wouldn't call it "sticking" (in case you were planning on squirting WD-40 into it). Replace the ignition switch.

O.K., when we pull the harness from the ignition switch, the car still stays running...All wires comming from harness has juice, even when unpluged from switch...All dash lights stays on...This doesn't happen ALL the time, but when it won't shut off, it does...Is there anything that can be back feeding juice through the harness? A relay, or something?

Did somebody install a security system into the car? If so, that could be your problem. There is no quick easy solution. The wiring harness may be toast.

I think it might be figured out...The owner had a bunch of junk in the trunk...Metal Chairs, jackets w/ zippers...He had this stuff over his Amp, and we think a zipper was touching his main power wire, and his secondary wire, causing it to back feed through his fuse block...At least we hope thats what it is...

Very possible. Most of the strange power problems in Hondas is caused by installing security systems and big power amps. Most often they overload the wiring harness.

That wouldnt have any effect on the car not cutting off. If anything the metal would ground the amp out on the chassis, either blowing the fuse, or the amp. The amps case is a ground like a computer case is a ground. You would some hellacious sparks shooting from the trunk. If this fixed the problem then great. But im just saying that this would not cause that sort of problem.