2) Imo Gauss shouldn't have any projectile at all, considering the bullet's speed. Sure, air nearby may go wavy, but not with this engine.
Unless there're different kinds of burst, they do show a pro - I set Pacificator's weapon to shoot normally in quadriple mode (as per number of it's 'barrels') and it did display four things spreading around. AoE was single, though, maybe it's different for spread.
Dunno about Hit FX, but Light does display - can be seen at night with a laser rifle set to burst.
Unless there're different kinds of burst, they do show a pro - I set Pacificator's weapon to shoot normally in quadriple mode (as per number of it's 'barrels') and it did display four things spreading around. AoE was single, though, maybe it's different for spread.
Dunno about Hit FX, but Light does display - can be seen at night with a laser rifle set to burst.