"Flamethrower" (the wavy path ball gun) is perfect for a couple parts of the game where you can lay down. You fire and ever shot hits, and you are never in the path of enemy bullets or mobs.
In very narrow cases, yes. If I remember, spread has a specific rate of fire which is fairly slow compared to flamethrower, so you can clear very specific targets faster with flamethower. Again, 99% of the time Spread is going to be better.
MUSHA has this with the orb circle shield/weapon thing (I never learned the name). I used to think this was bad game design but even if it was an accident it's interesting trying to bend your way around a game to keep from picking up stuff you dont want.