FMSE18 player's growth potential!

Hi, Is there possible to assign growth potentials?
Also is there any possibility to change regens portrait?

What do you mean by "assign growth potentials"? If you want a projection of how a player can develop (which clearly is a scouting feature), you can use Genie Scout that has this option already.

Changing a regen's portrait seems like a pretty vague thing to accomplish. Even if it was possible, you'd need certain presets and whatnot... which would make this a pain to put together. And I'm not so sure a lot of people would want such feature. I know they want better hairstyles, but that's about it.