Yeah, maybe - I'm switching to brushless soon anyway on HWII so it'll not be too much of a problem. It's not happened again though so that's a good sign! HWI's getting the old brushed ESCs, maybe motors and then HWIII will use whichever drive system proves itself to be most suitable... I'd like brushless but it depends how it works - if it ends up not being suited to that shape/design/weapon then I'll stick with standard brushed. Brushless would be better though.

That's the best thing too, we both had no idea what we were doing going into this (granted, I had a lot of help from Mario which I really appreciate and has definitely been the reason I lasted more than 15 seconds in the arena) but now we've been part of a competition we know exactly what parts of our machines work and don't and what to change. For me, it's definitely been the most useful part of the ongoing design process!
I'd just leave Hatchet for a while too, give it a few more events and then work out what works and what doesn't - the featherweight shows at heavy events are utter chaos so that'll test your design loads too! I think the general outline of your machine works great, but the internals and chassis need reworking slightly as you've already mentioned... Having LiPos and TZ85s will sort your drive, the drills should still be fine and your axe mech is still fine - refine your body shell and you'll be fine! Just have some angles and try not to leave any 90 degree corners and you'll be sorted. Also, you could try 3mm Hardox for the base, or Ti or something if you wanted to go that route, it'd be pretty rigid!