IMO, if you're powering all four wheels, it's gonna be a waste of space. put all your drive on the back wheels and have the front wheels on axles, that way you should (in theory) have more space and weight to have a bigger disc and more batteries.
Make sure to make the top armor piece overhang the wedge a little bit so it can't flex up into the blade. We don't want a repeat of Hazard vs. T-Minus happening here.
I guess you can pop different bits into the hole on top, like an interchangable weapon port. Like a USB slot, almost. If my guess is right, that's pretty damn awesome :D