RE: Velcro to hold wings on?
The Olympic 650 glider was a 3 piece wing that used pins to plug the outer panels into the center section, then they [IIRC] recommended using electrical tape to seal the slight gap [seam] where the panels meet.
Actually, I'm not really sure if the instructions called out for taping the seams or not..it's been over 20 years. This was a 2 or 3 pound plane that flew at 25 mph.
For a big, powerful aerobatic model with a fast roll rate I would be a little bit nervous about the velcro.