The firewall problem is easy to solve. in your flite box, place a 1/16 drill bit that will fit the electric screwdriver next to it. Put in a box of round toothpicks and some 5 minute epoxy. When you check out a beginners airplane, fix the firewall (unless he has already done that).
As far as the construction quality--I have see those fancy Edge 540 ARF's with absolutely NO glue on the wing carry-thru. That is none, zero, nada, nil - glue of any, repeat any kind. This detail is only discernable after the crash.
What do you do for that? I dunno, but somebody needs to pay...

Roger