My camper is still off from the winter. I'll try to take some pics tonight or in the morning. i was mostly talking about the bracket that bolts to the bed sides in the truck. These are special because of the aluminum body.
I have a different brand that as far as I can tell is identical to the Diablo. I believe they come from the same factory. Yes mine is short. Build here https://expeditionportal.com/forum/threads/fiberglass-truck-camper-build.190779/
I don't know the official rating but I would say the weight would not be a problem. There is no way you will fit two big people up there and any two people would have to be spooning in a slight fetal position.
Ya, windows might be a little too big. They sure do provide nice view though :) The overhead storage were a bit overpriced but really easy to install and quickly removable if needed. They fit so perfectly too!