RE: What fight charactoristics would you expect from a nose heavy plan?
Likely the wing loading is simply very high
Here is the sad fact of most ARFS like this
They are simply too heavy for their size.
So to control the model - speed has to ALWAYS be higher -for any maneuver
Only two things count
weight to size and power to weight - In these models, all the rest of the "trimming" of ailerons/flaps airfoils etc.. is a distant second.
Shifting the CG aft will only increase the problems.