No questions about it. Not to sound defensive, as I'm not trying to be, but look at wakeboarding in the same light and ask the same question.
[that's where I'm coming from with those questions.. years of wakeboarding, both driving the boat and riding behind]
Answers to a couple of your questions:
1. You could wear a life jacket, and it would be recommended on children. We chose not to. It's still in the testing/design phase...gotta figure out how the board works first.
2. Let go, swim to the top. Board will break, or the line will break. Board is buoyant.
3. Good point...we freaked the first time someone new took it past about 10'. She was down FOREVER. You CAN watch the rope though, and there is a system in the works for OK/NOT OK signal back to the boat. Other boats: well, currently it's pulled within about 100' of the shore, in coves where there are no other boats active. Also pulled slow (put the boat in gear, that's it right now) with the flag always up.
4. Can't help stupid. I haven't taken it over about 15' down, but haven't come close to running out of air either. Talk of scuba emergency air canisters on the rider.
Thanks for the
constructive comments.