It sounds like there may be problems with your code but we've never seen that so can't really help with it. And of course you can't know how well it works with no motors. Without the motors it doesn't do anything useful at all.
But as already said most drones use 2.4GHz RC systems and one reason is that these are a lot less likely to be disturbed by motor noise than a basic 433Mhz radio setup.
Steve