The fact he had to use Boateng, Vidal and Pereyra as AMs because he isn't given anything else is exactly why he says give me a real AM or I will change formation.
Pogba is a classic CM who is best using his physical and technical qualities by covering and winning of alot of ground. Also much better space to exploit for him deeper and wide with his skillset, then so close to the forwards as an AM would be.
You use players where they are their best, and Dybala is better as close as possible to the attacking third, he can be as creative as roaming forward as he would be AM, but difference being later would have him bit more lost and less dangerous since he isn't close enough to the decisive moments. He will have hard enough time settling in and becoming a difference maker, you don't make it worse by playing him out of his element and deeper as is.
1) He had Cassano and Seedorf to use them as TQ but he didn't, he even used VB over Pirlo and wanted to use pirlo as another cm, not as deep lying midfielder, and he did the same with Khedira in Juventus in friendlies, when he placed him on the Pirlo's place instead of Marchisio, so yes he did mistakes in his career and only time will show us if he is wrong or right about pogba and tq role
2) No, Pogba is not classic CM, because of his physical conditions everyone thought that he is typical african DM when he was young and joined juventus while we know now that he is much better than this, he is useless when it comes to defending, he is useless when it comes to b2b runs, we have move to him forward and give him a free role, he just need to improve his passing abilities and vision and the only way to do it to let him play under the pair of forwards, that's it, we have to give him the chance to become 2nd zidane or call it whatever you want, you dig his talent if you use him far way from the opponents box, that's why he stagnated in the previous season, he didn't make step forward
3) You use developed players where they are their best, while for youngsters you can find a better place on the field with your vision as head coach, that's what Mazzone did to Pirlo