SS Wings, couple of build questions

[Blain]

SS Stage 0 wings. (pile of parts, nothing preassembled) Right wing on rotisserie finishing up trailing edge skins.

Any advantage or disadvantage to the fuel tank bottom cover? Shows as optional and not included in kit.

Why can't the fuel tank be mounted before the wings are attached to the fuse? Way easier while on rotesserie.

Been measuring for twist as I build and its been very close to zero. Finished top skins and now have about 0.8 degrees (less the 1 degree) I'm thinking a slow ship with fat wing won't care. What does the knowlage base say?

Top trailing edge skins are unsupported on forward edge. Seems flimsy. Leave it be or add a stiffener?

And just to throw a gripe in, bought the $85 Codsgill deburring bit. Didnt last 1 hole. Hand deburring tool tests my patients. Anything else that has proven to work? Interested for the other wing spar tubes. Sheet aluminum that can be accessed from both sides isnt a problem.

[CanadianSheepHunter]

The factory will tell you that the wings must be mounted before you level the fuel tanks because of some twisting possible when wings are mounted. Im going without bottom fuel tank cover. The top trailing edge "forward edge" skin i think there is 1/2" aluminum tube supporting that.(not looking at my plane at the moment.