Your list is probably a good one - the toughest IMO is the rankings from about 10-25 - so many good to great players.
1) Impact on game including defense
2) Size is a component of that - in history, bigger and taller players have overall meant winning ball, not that a small player cannot become a force, ala Iverson but James has an automatic advantage everytime out with his size.
3) "Clutchness" part of experience
4) One half year (ala Yao) not enough to move into top ten but he will get there.