Weads,
You are on the right track and need to investigate "further effects" of controls and what is happening in "ground effect" among other things.
FYI it is described as "ground cushion" but actually there is no such thing.
The classic aircraft that stumps people in characteristics to fly smoothly is the AS350. The design accentuates a lot of the effects and you see people fighting them constantly when they are all "pilot induced".
With few exceptions 99% of all landings are slope landings. Understanding what is going on with the aircraft and a bit of practice and its a no brainer.
Shell out for Ray Prouty's books for a start.