Even though you can add classes to some extent, you can't change the classes available at the start of the game, and you can't give a character more than two classes. So you could not be a Soldier/Scout/Scoundrel, Guardian/Sentinel/Consular, and something else.
I also don't understand the reasoning behind some of the powers you mentioned. They seem overpowered, or otherwise not very true to the Force as depicted in the films. And there are already a lot of powers in the games like that, ones that exist simply to replicate a standard RPG spell rather than anything that's actually depicted in Star Wars. There are already lots of established Force powers that aren't represented in the game. I'd suggest looking there for inspiration.