Having never had kids I have no feelings such as yours, thank the lord. It must be terrifying seeing them starting out. However, you are absolutely qualified to not dictate but certainly guide them, firmly. The one thing they don't have is fear, experience, knowledge, skill, ability, judgement to name but half a dozen. You on the other hand have all of those in spades. Your children are embarking on many parallel apprenticeships and as with all apprenticeships there are rules, guidance, best practices, knowledge and experience handed down from those who know and do better, some of which should come from you and some of which won't.
I'm really glad that my dad 'guided' me with a really firm hand; when I was 16 he knew sod all, by the time I was 21 he had learned so, so much. Thanks dad.
Also, you are learned in the ways of the authorities and their views on motorcycling and it will, I am certain, all come crashing down sooner rather than later. It is almost an inevitability of our society's 'progress'. I'm amazed that when the car came along they didn't ban the horse, I'm sure they would these days. Once autonomous cars and trucks are the norm, bikers will merely be a hindrance to their technology and will come under increasing threat, especially if they are then the only casualties on the road. Giving them the ammunition they need to outlaw us now is just plain daft.
But, as with gun 'control' in the US, it is the daftness of the few that threaten the 'freedom' of the majority. Likewise, those who make the headlines for not toeing the 'norm' line on motorcycles, horses, bicycles, wings etc. are what threaten the freedom of the majority.
I have a very high tolerance of being very close to opposing vehicles at speed. Most bikers don't and I sure don't need anyone telling me how daft it can be at times but I also don't need anyone legislating against how I choose to ride and drive any more than you do when it comes to what to wear.
I used to ride into town in a shirt and trousers (helmet, gloves and boots) on a rare, hot summer's day because I was going no faster than Mrs. Grimble on her sit up-and-beg bicycle and in fact, was overtaken on the downhill stretch into Newbury many times by madcap lycra lout cyclists. These days I would never dream of riding without the three essentials and would be happy for them all to be mandatory.
Personally I can't see why I am not allowed to tinker with my own central heating boiler (gibbo is spinning and ranting as he reads this) but my distant neighbours are probably grateful it is not allowed. When it comes to some things, being allowed to take risks is best not left to the individual even if they are the only one who will be blown up.
The guy in New York could easily have been hit on the head at speed by a flying rock, lost conciousness and then there would have been half a ton of uncontrolled chrome flying into the traffic or worse, pedestrians. The idea that he was only risking his own life is fatuous. None of us can calculate the risk, we can only hazard a guess at it. Likewise, we can never calculate that the risk is only to ourselves.
Minimising the impact when we guess wrong is our duty to society, in my opinion.