Bloodyell Stew, why complicate a simple, very capable machine with all that lectric automation dead weight?
Just do it.
The only thing id like to try out that would increase rates, simply, is a teetering prop.
Firstly "Mad Muz", the plus or minus 2 inches is a strong recommendation, not a "you will do this or else". Please read the appropriate regs.
Also it is a strong recommendation that a horizontal stabilizer be fitted. A small flat piece of plywood isn't a HS.
.Agility is in no way related to stability.
You can be stable or unstable but still have the same level of agility.
The down side to the big HS asa fix for instability, is it costs energy, and the damping effect slows the rate.