Imo you make excellent points. I think instead of looking for talent, its likely more about making sure one is not handicapped in some particular way. Even players with certain handicaps can be outstanding, but clearly, some things can hold you back more than others. My point is, if there is nothing about you that is a big impediment, then great effort and coaching should be able to produce stellar results, given time and resources.
The coach's kid is almost always a top player on HS teams, even if he seems to lack talent. And like you say, the kids that are starting with good coaching at 5 and stay with it will nearly always be good. People will all say the have talent when they see them at 14. Few make it to #1 on the world, but lots of people who put in the effort become outstanding or even Masters.