Good post,I personally believe to mount it solid and make it strong.

As to the bending the frame,If the impact is great enough to bend the frame I don't want to be in it when it happens <img src="/forums/images/graemlins/scared.gif" alt="" />.

Also if the frame get's tweaked alittle and the rest of the vehicle actually survived'd the incident,then i say poo on it and drive.As long as the bend is behind the front axle frame mounts and the links are ok it will drive good even with a tweak'd rear frame.
Unlike leaf sprung vehicles where alot of tweaking happens between the spring mounts....causing it to crab.

I want my bumpers to not move and crumple why?Because the more they can crumple,bend etc. means the main force to the blow can be directed at the body,and sheetmetal ain't gonna slow down 4000#.So if my 100# of steel can slow down a vehicle before it folds itself into/onto my body,then <img src="/forums/images/graemlins/cheers.gif" alt="" />

Sliders can help also,if they stick out past the body.I was hit in a parking lot by a lady,not fast but I guarentee that the doors would not have been able to open without the sliders----and yes it tore up the front of her car.
Now if she would have been going alot faster It would have flipped me over,that I'm sure,but the initial impact would have been the sliders and not my pelvis.

Bansil's .02 for the weekend <img src="/forums/images/graemlins/patriot.gif" alt="" />