I don't really follow what you are on about, the problem as I see it is that if you mount the spindle and generator in line it will get in the way of the tail when it furls with the normal set up. You could mount the tail hinge higher so that when it furled it would go over the top of the generator.
If you are intending to use a belt drive then it would make sense to balance the weight on either side of the yaw pivot but you would still need to mount the motor/spindle unit lower so the tail doesn't foul the belt.
As long as you can arrange things so it doesn't foul then the normal furling system will work perfectly well.
If you use any form of belt drive then it is the spindle offset you must consider for the furling. Balance is nice but not that significant, you loose balance as soon as the tail moves anyway.
Flux