Few issues here...

Batteries: I dont know if polycarb cell holders would protect the batteries from impacts; polycarbonate is quite stiff (thats why Killerhurtz and Terrorhurtz are almost completely made of it ).
To be honest youre better off just stating it has shock proofing inside, having foam around the batteries and slack wires would probably be a bit better (insulating the entire pack rather than, say, just the cells). I could be wrong here of course.

Bosches are comparatively heavy (3.8kg for one) compared to other motors you could use, LEM130s weigh 3kg and provide more peak power, Mags are around the same (although theyre a bit risky on 36v) and even Littons would weigh less than Bosches and do roughly the same on 36v.

As for the weapon...SERIOUS damage...how serious? Even though its purely theoretical, the Team Cosmos calculator provides a good indication of the damage something would do. (just run the ring part through the calc and treat the hammers as extremely big teeth). Also Id like to see how you get to full speed in 2.5 secs, spinup times have been a black art to me for some time but that still sounds suspect :P

Otherwise good, and nicely in weight by the looks of it.