A lot of these aren't balancing issues but general design. It's not imbalanced for everyone to have the same range for example.
Regarding levels, abilities are normalised in terms of damage, the only thing that's not is the level required to unlock one in the first place. But I don't personally think it's that big of a deal when it takes so little time to level up in the game.
Shotgun damage, are you suggesting they turn down the range, or decrease the damage? Because the shotgun is really only good for close quarters combat, which is a major disadvantage that needs to be compensated for in terms of balancing.
And the fusion rifle, in your opinion how much extra time should be added to make it fair? Bare in mind if you miss, it's pretty much game over, so you need to account for and compensate for that too in terms of balance.