If the prop is going to touch the "cheeks" it will likely be at idle. At full-throttle the prop is being bent slightly away from the "cheeks," so check it at idle. MANY planes have the engine offset to counter the torque of the spinning engine-mass and prop. This torque makes the aircraft want to yaw to the left, so the engine is offset to the right to counter this tendency.

This is generally not much of a problem on a trike landing gear (lg) set-up, like you have, but will still be noticeable with rapid throttle increase, especially on the ground. Just don't "slap" the stick. Apply throttle gradually. Tail-draggers, especially short coupled (short distance between main and tail gear) such as the Cub, are notoriously hard to handle on the ground due to this condition. Just keep your throttle application gradual on take-off or touch-and-go, and all should be fine. This is a good idea for any situation except for emergencies, and later on, aerobatics.

If you don't have one, find an instructor. Just go to the field you'd like to fly at and ask. Then ask your instructor for if he has any hints/requirements for your assembly/training.

The LA comes in around 1.0 horsepower (by OS spex) and the AX around 1.6. The LA should be more than ample to tug your 5# trainer about unless you are at high altitude like Denver, for instance. (Denver R/C Eagles field is at 5,500' MSL). Hope this helps, not that others haven't give good ideas already.

Best of luck!