RE: which plane to use for instructing
Well, that's odd. The Nexstar is a favorite in our club. Mine went through three students and helped teach them all (including me) how to fly RC. And, as far as I know, it's still around. Mine did not have any of the problems you described. I did not use the AFS, in fact, I removed it as well as the installed radio and put my Airtronics in.
CGr.