I haven't started building yet. But on most arfs I add some support. I plan on beefing up the firewall like I do on most models. As for the covering you might want to try putting monokote trim solvent over the seems. My father and I do this on most models. It works real well especially on ultracote were seems coming up are pretty common. It works best if you do it before it ever gets fuel on it, but it should help. I know nothing about the engine and it will be my first gas engine. I was going to put a ys 1.40 in it, but wanted to try the combo since my shop is planning on carrying these models. I'm interested to know if it has enough to pull out of the hover down low.