I have a couple of questions, TheWeb. I, too, though, do not want to be rude, but wish to contribute to help you contribute.
First of all, you said you programmed the tech. For it to be this way, you would have to have used a microcontroller, like Spidey uses in the new film. However, in order to do it this way, it would quite frankly only take about 10 or less lines of code to release these at the touch of a button (that is, unless you are doing a double tap like me), so I don't exactly understand why it would take you hours of programming. Second, why use a lever? It would just push up on the shooter and push it off the power source and/or wrist.
Also, if you have all of the chemicals mixed beforehand (except the activator), it could 1) harden in the canister and clog up the shooter, and/or 2) cause an unwanted reaction and kill the shooter.
All in all, I think we need to know more about the tech if you actually want to contribute to this project; because this "tech", as you call it, seems to be the main portion and makes it look like the rest does nothing until it reaches that point. I would suggest telling us more about the "tech" portion, and then we'll see your ideas from there.
Once again, only trying to understand.
EDIT: It seems, since you're at Raspberry Pi, that you're more than likely using Arduino. Still, I stand by what I said... only about 10-15 lines of code, at most.