Either there is too much downthrust in the engine, which you compensated for with up trim, so that when you cut the throttle the trim forced the nose back up... or... and more likely... the C.G. is too far back.

Disregard the manual and put the C.G. another 1/2" forward by moving the battery pack to the front of the plane... then as everyone else has said, tone down your rates and add expo.


When the plane is tail heavy it will be extremely responsive and difficult to control so you have two problems you have to deal with at once.
Any movement of the elevator causes the nose to bob up and down as you attempt to compensate. Letting off on the throttle will seem to improve things a bit, but as you've mentioned the nose will come up until the wing starts to stall, then the plane is difficult to land.

Bring the C.G. forward. It will fly this way ( probably far more easily too ). You can always adjust it back to your liking later.