One of the weird things about this game is how they’ve developed a playstyle for each character but then had to figure out how to give you a skill tree so they lock up character defining traits behind level gates. Iron Man’s shtick is that he has three different project type but it takes a while for you to unlock each one and then build out their movelists. His laser is a crowd control thing since he spins around in circles spraying lasers everywhere, and if you have an elemental perk like Pym you can just shrink entire crowds in a few seconds. I thought his rockets felt relatively nice since it blasts people away but they drain your meter too quickly because they’re the heavy hitter option.
Flying is whatever because the level design has no idea how to make interesting levels that can accommodate flying characters and ground based characters. It can be useful if things are getting too crowded around you or you’re trying to get a line of sight on something far away, and it lets you get around faster on one or two vertical AIM maps. But I don’t recall there being much use for it in combat overall. I know there’s a carpet bomb move with the rockets but I always forgot to try it out because I never fly.