New 5th wheel purchase. I think we have a lemon, need advice

Gee the windows were installed crooked in the slide when you took possession.
Gee the window blinds were slanted when you took possession.
Gee there were missing and crooked screws when you took possession.

Drawers come out during travel due to your driving and our wonderful roads and the dealer and manufacturing can hardly be held responsible.

Take your rig in for the items to be fixed. Be aware that it will take a long time. Better yet learn how to fix the little things.