I do not think that you have any type of frame damage. This chassis is one of the most tempermental to align. It is very touchy to adjustments. As Iam sure that you know the caster and camber adjustments are done with offset bolt kits. This makes it almost impossible to get the alignment perfect side to side. It takes a great deal of time to get this alignment to what I term optimal. Keep in mind that most techs are paid less than two hours to perform all these operations. They are only required to bring the adjustments to with in factory spec. So please do not fault the tech. They are doing there job as best as they can.
The approch that should be taken with your car is to have the alignment done again. I do
not have the most recent specs in front of me. Your dealer will have them. I would insist that the cross camber should be no more than .2deg less being better. The factory spec is.5deg. The cross caster should be no more than .1deg. The trust angle should be 0 plus/minus .02deg
The toe should be set to the middle of the spec on each side using the win toe adjustment procedure if avalible. (Hunter Equipment) Also the wheel speaded device must be installed during the final toe adjustment for this adjustment to be accurate. On your crown drift concern. If the car is crown sensitive this is usually due to a high cross caster. But can be caused by camber as well as tires. These cars are known for following the crown of the road. Drifting away from the crown. But it should not do so suddenly or harshly.
I known that if you spend wome time around your dealer that you will find a good tech that understands the alignment procedures and I will bet that he can fix your concern.
Good Luck and happy motoring