spin question
 

depends on the aircraft.

R/C trainers are designed to be spin resistant, and self recovering. (Like the full scale Ercoupe is virtually spin-proof) Some models are as hard, or harder to get out of a spin than the full scale planes they are representing.

Changing the center of gravity rearward, and adjusting both of the ailerons downward (2 to 3 turns on each clevice is a LOT... and will make snap-rolls tighter.) will make your trainer behave more like the full scale aircraft, making it require positive action to recover from a spin. But... be careful, you can make it impossible to recover from a spin if you adjust things too much.

spin question
 

And then if any of you have built some of the SPAD airplanes, you can get some of them into a flat spin that they just wont come out of. I've also seen one RC airplane go into a gyroscopic spin, and it wouldnt come out. Luckily, the farmers field was freshly plowed, and it had just rained...