I realy like this one! usualy when I here of the idea for a hover tank I think "Oh! stupid idea!", cos what hapens to the recoil? unless you chave some kind of super futuristic force field technology?
But with this one it looks not too futuristic (one of the problems with future units, what do you use as the missing link between 1990s tech and 2050s tech?) and from the shape of it you can imagine a low tech "articulated foot" being lowered under the ruber skirting to stabilise it during firing. The foot would provide exelent stability, and could be drawn up inside the body when the vehicle is in motion!
All in all this would make an exelent near future amphibious artillery or amphibious heavy support gun.