You listed a bunch of perks but none of them are related to grenades. For a class to be OP it does not matter how many nodes they need to use, you could use the entire skill tree for all I care...that grenade and flame shield are OP as -blam!-. 1 v 1 in medium/close range sunsinger wins because the range of the melee is sniper class while the damage is shotgun class and on top of that you even get a shield.