I don't know the specifics on the forces at play (maths scares me lol) but what I would mention is that you'll definitely want strong materials for those legs, or protection for them, given how destructive things can get - and make sure you've read up on the rules and actually get your 2 degrees of freedom in there to avoid it being classed as a shuffler, because you don't get the weight bonus for that. I'm sure you already know this, though! I would try to avoid the pneumatics too where possible unless you're confident you could have plenty enough for a full fight and then some because it sounds like there'd be quite a lot of CO2 usage at play...

Other than that, it's awesome to see a potential walker out there - certainly something different, hope it goes well!