I’m going to reiterate…Heat! Dealing with heat is huge in space environments and should be the determining factor for how long you can fire. Let the autocannons be belt fired, but if you fire too long you will melt your barrels. Maybe the sunside barrels melt faster(I know dev time and complicated and all that, but still it would be a neat feature). Allow us to equip/upgrade our ships with better heat sinks and/or radiators to dissipate heat.
One of things that I think Elite did well was heat management and in my opinion it should be in any space shooter/sim worth its salt. Heat is something you cannot just hand wave away. It’s everywhere! And the internal temperature of a ship with a whatever GW(TW? Not sure what sort of handwavium powers our ships) reactor on board is going to generate a TON of heat.
As for the ammo debate, let each type of weapon have their own ammo pool shared across the ship. The belts all grab from somewhere after all. For missiles, let the pod/wing hardpoints fire first…if your ship has the capacity for more let there be a reload timer to reload the pod or belt them back onto the hardpoints.