1) I spaced. I thought you meant post play, as in like center or power forward. Not post playing career. Anyways, how does his coaching career so far scream he can teach the game? The majority of his experience is in the NBA, which itself is pretty different than coaching in the college game, and most of that was focused on helping shooting, not running, or help running, the team as a whole. Just because he has some experience coaching, doesn't mean that experience screams he can coach. If it wasn't for his playing career his coaching career wouldn't get him a first glance from any ACC school, and if it wasn't for his association with GT he wouldn't be considered here anyways.
2) isn't even an argument. You can do certain things to help those, just lie you can do certain things to help athleticism, but you can't coach your way to elite levels in those areas. It's experience and natural ability. His natural ability was refined through hard work, just like Lebron's natural athleticism was through strength and agility training.
3) And you ignored the fact that only having 1 year now, or 3 years when someone projected him, in college means he'll have limited networking to get good assistants. Questions recruiting isn't limited to players, it's also in attracting good assistants.