Lookin' good.

My experience with the the top wing was similar to yours:

* Lack of straightness in the wing can be (will be) corrected when you sheet the other side. As it says in the instruction book (when you get to that point), sheeting the other side "sets the shape of the wing." And, indeed it does; the wing will be very stiff once the sheeting is completed. One caution here. When you're pinning the new sheeting down, the wing may have a tendency to break free of the building board (because there are no alignment tabs on the underside) as you man-handle everything into position. So, you may want to put shims under the trailing edge to help keep the wing steady on the board.

* I, too, had some gaps at the leading edge of the sheeting. I did the attachment in two steps, and this helped to keep the gap small. First, with the sheeting tangent to the leading part of the ribs, I glued the sheeting to the leading edge "spar" and to the ribs at just this point. After the glue had cured I went back,with the sheeting wetted, and laid glue over the tops of the ribs and the main spar, then pinned in place. (It was at this point that the wing wanted to separate from the board.) I used thick CA to give me a bit more working time.

Keep up the good work.

P.S. Wrecked an Utra Stik today at a club "Snow Fun Fly." Was worrying too much about how the plane was flying with the skis, and lost control on the third loop in the required sequence. Now I, too, have got a project for the cold weather.