The kit doesn't need any "beefing up", it's plenty strong as it is, and you'll just add weight you don't need. You can even leave off the plastic leading edge cover if you want.

The biggest thing to be aware of when building it is to make sure the spar sits all the way down inside the wing and doesn't stick up and leave a bump on the top or bottom of the wing. I'm not sure what the problem is that leads to this, but I've seen this on several of these planes, and it really does hurt the performance. It might be that the spar slots aren't always cut deep enough in the wing, or the polyuratane glue is lifting the spar up. Whatever it is, watch for it, and keep that spar flush with the wing surface.

For flight trimming, set the elevator so that you can hold full-up for at least 2-3 turns if not forever with out snap-rolling out of the turn. A lot of guys who are new to combat set their elevator travel way too high and wind up spinning in to the ground, espeically in SSC. (the good news is that usually you don't break anything if you do spin in, espeically if you remember to cut the power before impact. Nothing saves airframes more than cutting power before you hit the ground).