RE: Foamy
Jeff the holes help dampen the control surfaces, lighten the airframe, but most importantly provide some drag to the plane. It is very common to see these in the states- either holes or triangles near the TE.
I flew this plane today and noticed how much better the plane flew with the 480 2S thunder power as compared to the 730 thunder power 2S pack I had. The biggest difference was weight. I realized there are a couple of quick things to do to remove some more weight. First, I removed about 12 inches of unused wires and connectors (4 inches times three) for the three leads going between the speed control to the motor, and then soldering the now shorter wires together. I hardly ever take out the motor or speed controller but if I need to then it only takes a few minutes to de-solder the wires. I also took a knife and cut a good portion of the prop hub down. These two things took around 1/4 to 1/3 ounce off of the plane. I could not believe how much of a difference this made. The plane flies with much more authority (it may have been loosing some power from the longer leads as well). This change also moved the CG back a bit closer to the recommended spot (5 inches from the TE). I also bumped up the elevator throw to more 3D (less of an F3P rate). Now rolling harriers are so much nicer.