Megadeath *was* seriously nuclear explosions and so on, so it makes sense he'd have a funky reactor. Given that Megadeath worked in Stanix, which seems to have been the back of beyond even before he blew it up, it seems unlikely Needlenose would be there. Insufficiently metropolitian for him, yes.

Does Spinister have a reactor of some sort? He carries fusion bombs and a nuclear-powered flamethrower. Doublecross, Cindersaur and Dogfight all have similar fusion-powered flamethrowers ...

Noise issues would make life interesting for a stealthcopter, yes. Also make his Nebulans deaf.