Please let us add/train playstyles in Career Mode

exactly you need to implement a way to add playstyles like a real part of the game not through a glitch..

A way to do it would be this

couple examples

1. 30 out of the box goals you unlock power shot

after 100 goals powershot +

2. if you successfully use skill moves 

after 30 you unlock trickster

after 100 trickster +

3. after 30 finesse shot goals unlock finesse shot ability after 100 goals finesse +

4. after 30 completed driblings unlock technical aftter 100 dribblings ability technical +

you can go on and on

or you could implement it somehow into the development plan so that you can unlock it there

or if you are over 85 Dribbling 

you receive technical automatically and over 90 technical plus

There  are so many different ways you could add it to the game

it is really funny cause they created a nice feature but somehow did not think it through