A relatively high FP cost should negate that, besides, guns already get a lower bonus. Besides, do you have a better idea? There needs to be more Force Powers. You can't really compensate much for the nature of a long range weapon without intentionally nerfing them. There's a reason so few people fight with swords anymore.
Honestly, there should not be some inane 'gunner vs. Jedi' debate, because such a side is imaginary, seeing as how there isn't a restriction except on what you buy.