On the wheel well, I would drill new holes in the good material and reattach using the new holes. On the bed frame, I would straighten it out first and then also drill new holes and reattach. I have had to do this in every Trailer/Motorhome I have had. I think Airstream used 4-6 screws to hold the frame to the wall. I usally use close to a dozen. If you can get on a rib or two great. If not just get it supported and you wil be fine. I tend to favor self tapping as they drill the hole and then fill it themselves. Less wiggle room later.
Before you do these repairs there is a bigger question. What caused the damage, and has the cause been fixed/corrected? If not you will be drilling more holes again soon..........
WBCCI #5501 AIR # 49
1978 Argosy 28 foot Motorhome
Wise men talk because they have something to say; fools, because they have to say something. -- Plato