I love this site too. It's even better when people put a description of their question in the subject field.

1) You don't need to worry about the tank slipping out backward, at least not on this trainer. Just make sure it is a snug fit.

2) Check the CG with the tank empty.

3) Make sure your radio complies with modern tuning standards. Take it to a hobby shop or tell us exactly what you have.

4) Good luck.

Tom