RE: How To - Plug In Wings
Looks like the control surface is molded separately. If you go to the Composite-ARF site and download some of their instruction manuals, you'll find more information than what's out front on the site itself, including photos of the inside of some of the wings.
For the wing tube, I would use a block with a hole bored in it to create a jig, and adjust the angle of the wings as needed. Some of the expensive kits, like the ZN Line Pattern planes have this done by CNC machines, early in the process, but you can achieve the same accuracy if you're careful.