I'll tackle these in order.
- Lateral balance: if you side-mount the engine you will indeed have abit of a balance issue. You remedy his by adding weight to the opposite wingtip until it balances. A nifty (and nearly invisible) way to do this - use white glue. This works if the kit has hollow wingtips made of plastic or FG. Drill a small hole in the tip, then squeeze in enough glue to balance the plane. Once you've got enough in there, stand the wing on the heavy end until the glue dries. You can cover the hole you drilled with a small patch of covering.
- CG should be on the spar. Shift your rx battery to suit.
- The CD has a generous amount of wing area for a .40-sized aerobat. Don't worry about the small amount of extra weight.
- Should be OK. A stronger engine wouldn't hurt, though. I'd put one of my YS .53 four-strokes on it in a heartbeat!
