John I've heard you mention some of your cars problems before, but I don't remember you describing them in quite the same way. At least not the part about your car "darting" to the right during traction loss.
To be honest, that almost sounds like your Traction Control is acting up, and causing (just one) of your front brakes to be applied to help straighten your car out during a skid.
I would disconnect the TC by unhooking the "middle" wire from the little "Black Box" directly in front of the battery, (and try driving your car over some of the obstacals that you mentioned) to see if it still reacted the same way. If it doesn't, then tell the dealer to look into replacing your cars computer hardware controlling your cars directional stability.
Without actually seeing your "door fit" problem in the "flesh" (so to speak) it's hard to diagnosis. There does seem to be a larger than normal number of complaints about door and window "alignment" with our cars, and I would think that would be a more likely answer as to why your door isn't shutting properly, and the wind noise.
I'm not saying it's impossible your cars chassis is coming apart, but I think it's highly unlikely, and I would think there is a much simpler explanation for the problems you have mentioned.
I must say that your loyality and devotion to your Crossfire for so long without being able to correct its problems should be commended. Many would have "bailed" a long time ago. Good Luck!
By the way, have you taken it to any other dealers to see if they might have some better technicians?