On my rig the slide mechanism is at the bottom of the slide itself (above the cargo bay doors) and far away from the described damage area. I do recall seeing that with some Winne's the cargo bay doors move with the slide, do you have a similar setup? If so, it sounds like the damage may not just be the door, but perhaps also to the cargo bay. Maybe it is racked upward or to the side and is rubbing on something else. I would think that would happen before the slide arm would bend, but I am not familiar with your specific slide configuration. I would look before trying to extend/retract it any more to prevent additional damage. Good luck.
Lou
05 Travel Supreme Envoy