RE: Tail draggers, why are they harder to fly
Poor ground handling is due to poor pilot technique and poor model design. Unfortunately, toe-in alone on the main wheels does not have enough purchase to overcome either. Groundloops happen when the center of gravity gets outside of the wheel track, which happens much easier when the main wheel base is narrow, CG is too high, or when the landing gear is too far forward.
The most important thing in setup of the aircraft is to not have the landing gear too far ahead of the CG. While this makes the aircraft very light on the tailwheel, this is exactly what you want. The tail is held in contact with the runway with proper use of the elevator. With the main gear closer to the CG, it is much more difficult for the CG to get outside the track of the wheels, so ground loops are less frequent.
Takeoffs with conventional landing gear requires the use of all four controls.
The throttle application needs a smooth application to avoid torque problems.
The elevator is first used to hold the tail down, then allow the tail to lift off to prevent the wing from trying to fly off too soon in a stalled condition. You can easily run down the runway for as long as you want on the main wheels with the tail up. This both looks good and allows the model to gain flying speed.
The rudder to control direction from both effects of engine torque, prop wash and cross winds.
The ailerons to hold the upwind wing down in cross winds.
One you figure out how to do takeoffs, the landings will be easy.