Now that I have the system running, I had thought of something that I wonder if any one has tried yet and maybe knows the answer too.

Using multiple coils, not just one trifilar or quadfilar coil, but say 2 quadfillar side by side would it be possible to use the one self oscillating circuit to run Both coils? Is it even possible?

If your going to charge a large bank of batteries it might require more than one coil to charge them all. Using one coil strictly for the oscillation would allow the other coils to be used strictly as slave coils for output, freeing up at least 1 winding on each coil to that effect.