large scale gas power a/c
 

Could you safely use a tactic 650 r/c system in this type of plane?

Yes. However, just like you'd do with any other equipment, make a careful range check before each day's flying to be sure of your aircraft and radio installation.

Has anyone just used this small a rx with high power servos and not had some sort of power system between rx and servos? I am concerned about the rx handling the current load to the servos.

The receiver isn't the problem. You need to make sure that your battery pack and switch harness can handle things.