Forks Twisting without falling off

Might be at the point of taking the forks apart and checking both inner/outer tubes for straightness and also the axle and triple clamps.

If your fork tubes are straight and nothing is bent or damaged, this problem can happen when the oil heights in each fork are vastly different. If one leg has been ran long enough with a leaky seal or if only one fork leg was rebuilt and had a largely different oil volume put in it, it can change end of travel loads in each leg, causing them to twist. The twist can occur from one leg hitting secondary dampening and the other not (think one spring seat is in the oil bath and the other is not), twisting or flexing the axle and essentially "walking" the leg with less dampening around due to the load plane of the axle being off center and wanting to move away to the area of least resistance. Since you are not the original owner and don't know the history, doing an oil change or rebuild and properly setting your oil height in both legs would be the best place to start for you, not only to try and solve this problem but also to simply maintain and care for the bikes that we spend so much of our hard earned money on. 

I know my RMZ used to need fork bushings every 20 hours. I wonder if that could have something to do with your issues.

Are your steering stem bearings in good condition? If they are blown out, the top and bottom clamps can move enough to make the forks twist.