Re: Mechanical Trigger Failsafe
Yep, as illustrated, I suspect the line of the trigger release mechanism will get wound round the chord/parachute/whatever, pull taught and lead to premature ejection of the rocket, given spinning seems to be such a problem. A spring-based system is likely to be a safer bet, barring jogging up and down during any violent spinning.
The concept of the parachute giving a tug to eject the rocket is so appealing, however, that I think it should be worked on further. Perhaps the swivel mechanism could be placed above the chute and the trigger chord placed inside a straw to keep it out of harm's way?