Build your Eagle with the low dihedral it is a stable plane and with ailerons the higher dihedral doesn't work as well.

The sanding jig provided in you kit does work very well but your jointer will work also (just be careful not to remove too much material) I usually use a block plane to rough it in and the finish with that sanding jig (been doing it for years).

The rudder will be OK after covering it will be sealed.

I flew this past summer at the TRAMPS field in Traverse City, they a good bunch of guys and have a training program (no fee). They have a new field (haven't been there yet) and because of noise problems after their first activity their they have to meet a noise requirement of 95db at nine feet, it can be done my plane registered 89db at their old field.

Contact the AMA for club information (Traverse Area Model Pilots Society). The club has a very good list of what has worked to meet this noise requirement and will be very helpful.