Great idea, specifically the warning system to indicate a "loaded" mechanism. We have a microswitch that tells the software when the latch is latched; we'll also use that to turn on a light or indicator of some type.
Our kicker does not extend beyond the frame perimeter (if nothing breaks!
); we intend to make it so it's difficult to get a hand anywhere near the moving parts. We also will fabricate a "safety latch" that our drivers and pit crew will carry with them - if the mechanism is armed, the safety bar is installed as a secondary way of preventing accidental firing.
I also like the idea of driving around with the mechanism disarmed - our arming system takes just over 1 second, I can see us re-arming only just before taking a shot, not just after. Not sure about that though.
I also want to consider a way of firing the mechanism just before the match ends (with a ball or dry, no matter) so it's safer after the match. Need to think on that.