If the weight you are removing has little to no effect then I would call that very nose heavy. Not that I am suggesting removing a bunch of weight. I would continue removing small amounts at a time. Everything you are telling me is leading me to beleive you are still nose heavy. I would suggest measuring out the wing, finding what the mean aerodynamic cord is and then determine what percentage you are at now prior to any adjustments. For that airplane I would expect the ideal CG to be very close to 30%. As you move the CG back your elevator will gain sensitivity, do not mistake this for instability. Just reduce your elevator throw. Thinking of that, it is also a good indicator of forward CG, for the intruder having elevator throw of about 1/2" up and down would be plenty.