Starbound would be way more epic if the bullets were bigger, and glowy because they're hot. Casings/shells should eject from your gun when you shoot, and there needs to be more kick and screenshake. Heavily bass-boost the gunfire, and make guns take ammo based on weapon type. Rockets for rocket launchers, grenades for grenade launchers, etc. Need I mention bullets and shells? Energy guns could still take energy. This stuff would make guns feel way cooler to use. Currently ranged weapons of any sort feel kind of wimpy...
They won't do ammo. It has been brought up many times. Personally I don't care for ammo. It is micromanagement. Plus, if you think of the guns working like they do In the Mass effect universe, then they are still physical projectile weapons, but don't have shell casings. They are just a tiny sliver of metal being accelerated to 6% the speed of light. The kinetic force is that of a small bomb.