Ground just protects from extreme electrical charges/discharges. It carries no "mechanical" importance other than that. It does how ever cause inference when to objects aren't 100% on the same ground.
Removing the "neutral" ground just simply removes the interference. I didn't believe it till I had my system fully apart and it was writing...and I got excited....and then eventually touched the ground wire....and it stop....and then I eventually figured out what made it stop.
If you want we can chat over an IM or IRC if it helps any. BTW You won't be damaging the original NAND's...I don't thinks its possible. So having a backup hardware is almost useless...Its the firmware you need to worry about.