yeah mine bend too but that is because you may be putting it under extreme stress like bending them with your hand, during flight it does not have the much stress unless you max out the your servo throw and it pushes the wood farther than the control surface can go. It does not take that much throw to move this plane around. So you should never worry about being maxed out on servo throw.

I have a 1100mah battery on and that last me at least 6-8 long flights and my voltage is usually around 4.9 or 5 when I stop flying, so I could fly more if I wanted. I do not know how the on board glow will effect the battery because I do not have on board glows on my planes

The dihedral has to be set when you glue the wing half together. I used a heavy book on the wing that was touching the floor and I prop something under the wing that was in the air until it measure 6" from the floor. Let the item prop the wing until the epoxy fully cures (at least 10-12 hours). Once it cure your will will be set with the dihedral. If you just Glue the wing halfs together the dihedral comes out to about 5" (I think, it has been three years since I built mine) which is below the recommended.