Sorry for the delayed responses - time difference.
Do you know if any modern AFVs have the fuel arrangement you mention? I would guess that the foam while making the fuel storage more stable, would significantly reduce the amount able to be stored in the same space, and a reason the military wouldn't fit foam? But i'm ready to be informed different, is there any AFV's with foam filled tanks, even retro fitted?
Honeycombed or foam filled tanks don't slosh, one of the reasons F1 cars have all switch over to them. Even draw from each means little trimming.
if anti-gravity is a potential levitation device...that would, in effect, allow the tank to utilize the earth's natural magnetic lines for motion...correct ? Given zero weight, one would merely have to overcome inertia...so, light weight tanks would be an advantage in manouverability....plus, less weight=less power required for levitation.
I envision "reaction panels/emmiters at all four corners for motion control...only issue...how to shield against EMPulses ?
I'm just a layman so some of the science to me sounds great but I'm sure there is more to it otherwise we'd all have hover cars right now.
However, what you've written ( and what i've been reading recently) all seems to be possible so naturally would be ideal for Hover tanks.
Funny thing is both models i'm working on right now for this challenge are more conventional, Big engine, big thrust designs. I'll save a compact AG HT for the future.