1 - Check out their website www.modelaircraft.org/ Yes, you can join no matter what you fly or don't fly. The have a less expensive program for electric park flyers.

2 - Membership is recommended for all model aviators because of the many benefits, but not mandatory.

3 - Check with your local law makers. Nitro planes can be very dangerous and are noisy. Which is not to say that electric planes are risk free. The AMAhas a park flyer program for electrics under 2 pounds. Don't attempt to fly without approval from the park management or local constabulary.