1. Yes ALL top level athletes have great internal ability, that's why they are top level athletes.
I don't think you are talking about the same thing that people are talking about.
I have had some top level professional athletes (football and basketball) including a multi time league MVP in my school and their knowledge of internal skills was just about zero. What they did have was a great sense of discipline, an intense competitive nature, and a pure physicality about them. Otherwise they were complete beginners in terms of ki development or internal stuff in general.
training professional athletes in internal skills is nothing new...