1) Huh? I have moved from a "you're kidding" to "mandatory helmet" country so have experience of both. As far as I am concerned right now it's just a thing you do and, on reflection, a good thing. No false security - just a "whatever" and, in my case, demonstrably a good thing. I have never been hit by a car (close though) but in my life I have come off several times due to tram tracks, intoxication, bad luck, gravel, ice. 3 helmets down - still going. I have no idea how any of those situations might have turned out otherwise but I can categorically say that my behaviour was not influenced by me wearing the helmet. It's not fucking bat armour - it's a sensible thing if you might fall over or hit the tarmac at anything over 10 km/h.
2) Don't know. Personally, I consider that a bike is a bike and I assume they're going to be a spaz, turn across or fall over, helmet or not. In fact as they are mandatory I consider someone without a helmet thinks they are "too cool for school" and more likely to be an arse rather than a careful road user. I can't speak for everyone.
I am sad you don't let your kids wear them and consider education instead. Also, hopefully you or any of your friends never have to scoop up a corpse or battered, mangled body up and put them through surgery & IC. Yeah, you pay your taxes so the guys who will do this are out there, but it's really best avoided if you can, for all involved.
Same thing for seatbelts - I think you need to spend a couple of seconds thinking if your right to exercise freedom to not wear one is really actually something you should be doing. Does it make you drive more carefully when you don't? Do you daughters not wear one so other drivers look out? [See also "baby in board" stickers].