1) Everything except Turret shots, though the hyper charged debuff still effects the damage you do to increase WF damage.

2) Ultimately Grenado Shot is more time efficient while Spread Shot is more TP efficient. In other words, if the monsters won't die within 30 seconds of spamming Grenado Shot, Spread Shot will be more ideal because you'll get more casts out which is more damage in the long run when you're not running dry on TP.