So you're proposing to either A) tether a child, or B) wrap them in a life vest for a multi-month journey? I don't care how much netting you have, it's still a dangerous environment. How many sailors do the USCG and USN lose annually? They're adults, professional sailors, in relatively stable vessels.

I've sailed on several vessels on day trips and multi-day trips. Yes, I'm aware of the difference between guy and life lines. No, my experiences weren't including rough weather.
Edit: I see where I wrote "guy lines," and you're correct, I used the wrong terminology. Mea culpa.

As for the requirements, I have a cousin that has the same license. We spoke about it on a few occasions, so I know, roughly, what it entails. Like I said though, near-shore isn't the same as open-water experience. For example, most folks aren't going to try and weather a hurricane 10 miles off the coast, whereas they probably won't have a choice in the ocean. Ergo, they won't have experience in that environment.