Tomtnt,
I didn’t use or like the straps either; don’t think they will help problem 2. I also don’t think changing the angle at the door stiffener will make much difference. I am considering installing the straps from the lower FORWARD door corner to the upper FORWARD corner, combined with the strongback stiffener to address problem # 1. A good material for the stiffener would be the trailer bunks that were not used on my TTrailed.The window sill and the window itself do not provide enough stiffness to the forward door edge between the hinges when compressed against the foam. It is straight when the doors are open.