I would like to address this post at face value, and use myself as an example. I believe Vlade is more qualified than me for this job. Here are some things he has over me that I think qualify him more:
He has played professional basketball in the NBA experiencing first hand how team dynamics work on the floor, what is required to win, what skills complement eachother etc..
He has experienced an NBA lockeroom with all of its dynamics and what effect that has on winning.
He has been part of NBA negotiations before as a player, has talked to GMs, to agents, gaining first hand insight into how business is done in the NBA.
While all these things you list are fact, it still doesn't qualify him for a GM job. Otherwise a vast majority of all former NBA players would be qualified.
Not all former players make good coaches, GM's, scouts or TV announcers. And usually (not always) the ones that do went through some kind of process/progression to get there.
Jeff Gordon and Tony Stewart are among the best car drivers of all time. They know and were exposed to things we'll never know. But that doesn't mean they would be great at building their own race car or be better than some ham and egger that's been doing it their whole life. Most the mechanics that build and work to improve the engine technology weren't world class drivers themselves. (yes, I know Stewart has his own race team, but he isn't one of the innovative engine techs).
Conversely, there are lots of talented NBA/NFL/MLB/NHL front office personnel that never played a lick of basketball and rely upon their education and knowledge of sports. See Daryl Morey and Mark Cuban among others. At one point, they were just highly educated fans.