Alu box section for the chassis isn't out of the question (When you double the thickness of something you quadruple its stiffness) but I still think the material is inherently to soft for combat with that construction style.

4mm Hardox welded to make box section with holes in it to keep the weight down would do it nicely.

Like Nightmare it would be a one hit wonder against flippers or lifters. The Battle box was so big that Jim could get the disc up to speed before his opponents got to him. in the RC arena you just don't have time.

For the weapon itself I would use 8mm or 10mm Hardox then do weight saving similar to that of nightmare. Bolt each tooth on with two M8 bolts and that should make it plenty strong enough.

If you are going to have wheel guards have them bevelled or slanted, I can see the cylinders getting crushed with flat sides like that.

But with proper refinement this could be utterly lethal.