1) Strength and Speed are already "considered" in the other skills, I doubt adding new skills would work without a complete overhaul. You can view it like this: the current BB skills don´t show "pure" physical abilities, but their influence on the court. If you train a player to become faster, that might influence his OD, his Driving or even his ability to go for rebounds and blocks. While there´s no PURE skill "speed", the impact of a player becoming faster is there.
2) Proposed numerous times already in different combinations. Interesting, but a rather big step.
3) For what use?
Zwei Dinge sind unendlich, die Dummheit und das All...