If you cannot move the wings don`t move the c/g forward, you have to fly it tail heavy,
if you go forward with the c/g on a zero wing inc. setup your airplane will require uptrim and then it will pull in the downlines to the canopy and may`be in the uplines also
This will require engine down thrust and right thrust to correct,
your right rudder knife will require down elevator mix your left rudder will need up elevator mix
your inverted flight will need too much elevator input,
your 45`s upright and inverted will fall off line, your take off`s will be very hard to perform smoothly
and rudder will feel heavy
some of this is already the case I`m sure ,,,except the inverted part, and right rudder knife is probably ok the way you have it setup now...Am I correct ?

When you put the c/g too far back you won`t actually be nose heavy But it will feel like it ,,,,"only with the inverted elevator"
as soon as you let go of the stick it will go straight down.
ever tried to fly a hand glider tail heavy ? same effect except you don`t have a motor pulling foward.
your airplane will fly ok o-o except in the wind and upline snaps it will wander off line
you will have to lead the 45 down line snap with elevator to show a break
and the spins will be hard to hit the exit, you will have to lead the rotation and stop a little before your ready

To correct this move the c/g forward say 25% of the M.A.C.
put your wing 1/2 deg pos to thrust line
stab start at zero inc.
keep moving the c/g forward till up and downlines are straight and everything else will be fixed.
Yes putting nose weight with the wing at a 1/2 pos will actually make the airplane go straight up and down.
Bryan