RE: Aileron servo tubes
You can also just roll up a sheet of paper and tack it in place with CA. This is how the tubes were made for a Dazzler kit I recently built.
It's easier on a kit, but even if you are doing them on an ARF wing you could do the same thing. You would only be able to glue it at the servo bay and at the wing root, but it should hold just fine.
Good luck