Anything that releases joules is already limited by the amount of energy stored, be it the amount of propellant, or the capacitor for a LASER or electromagnetic weapon.
Duh. But it's much easier to store electric energy than it is to store explosive shells, metal slugs, or missiles. Coolant would be allow for more shots than a projectile weapon, but a lot less than an air-cooled laser(but at a much higher rate of fire). Also, I believe the laser's optics would eventually wear out and have to be replaced.
Indeed, LASERs are much less efficient when deployed in a slugging fest, but aerial combat relies not on armour, but manoeuvre-ability.
Hypervelocity weapons can still miss if turbofan-aircraft does not fly in a predictable manner, but LASERs are guaranteed hits on an identified target, even for scram-jet aircraft.
Aerial combat relies on detection and maneuverability. Detection is the battle of stealthiness & ECM vs. sensory systems - this was going to be implemented in WZ, but the entire ECM aspect died somewhere along the way.
Once detected, the first weapon to be used would be(and IRL, is) missiles, because of their very long effective range. How well the target knows about a missile heading towards them depends on the missiles own ECM & stealthiness, as well as the signature of it's guidance system if it's using active guidance(a built-in radar), and of course, it's closing speed. The longer time the target knows about the missile, the better chance it has of evading it.
Only once you close in to a sufficiently short range can you deploy a pulse laser. The pulse laser cannot be dodged once it's pointed at the target, so if a combat aircraft has expended it's missiles and isn't armed with an AA laser, or knows that it's opponent has a longer-ranged laser than it, it's best choice is to turn tail and run for it's life. It sounds like a cool proposition for future dogfights, and of course, the old cannons would be long obsolete.
Of course, pulse laser weapons can be further developed into electrolasers, by adding another capacitor bank that discharges into the plasma stream caused by the pulse laser's blooming to create a lightning bolt overlapping with the laser shot. It would do yet more thermal damage and knock out the target's electronics.
In fact, I think WZ's "laser" weapons ARE Pulsed Electrolasers given that they would be visible, and that electrolasers would have three-fold effectiveness against cyborgs(powersuit troops, i.e): 1) Thermal damage chips away the armor. 2) The person inside gets fried. 3) The electronics on which the cyborg depends get fried. If the laser pulse loses energy by blooming through a denser gas(smokescreen, dust, etc.), the electric pulse gets a thicker ion stream to conduct through. So cyborgs and aircraft would be at immense risk against this weapon, and ground vehicles would take some damage, though not as much.
While ablative armour is effective for heating beams, it is not as effective as much denser slabs of tungsten for a pulse LASER.
The true counter-armour for hypervelocity weapons would be a whipple shield, rather than standard kinetic armour plating.
Yeah, the true armor for mass driver weapons would be a Whipple shield backed by composite armor plating. It would also act as spaced armor, dissipating shaped charges to an extent and stopping squash-head warheads entirely. Add a capacitor bank to this set-up and you also have electromagnetic reactive armor, further countering out shaped charges and reducing the damage done by shattered hypervelocity rounds. Electromagnetic reactive armor may also work against the electric half of an electrolaser pulse by putting up a magnetic field and counter-current for a short amount of time to ride out the pulse.
