The higher energy cost is because they are being used on capships.. If we made a Capital ship's Battlerazor use the same energy as a Mini-razor, you could put 8 of them on a BS and utterly demolish any ship in existance. By necessity, the capship weapons have to use more energy. If you check the ratio, weapon's energy usage to the ship's energy capacity, the capships are better off. They can fire more often than a bomber can.. Bomber firing a Supernova loses around 80% of their energy.. Battleship firing a Mortar takes what, 20%? Thats around 4.5 more shots.. And lets not compare Supernova to Light Mortar.. If your going to compare at all, compare normal Mortar to Supernova.
You cannot compare fighter and bomber weaponry to capship weaponry in damage-to-energy situations. Know the expression, comparing apples to oranges?
The anti-capship weapons are actually rather balanced at the moment. Capships will be harder to kill next version, which I'm sure will make you happy, but its not very bad at the moment. If it weren't, do you think the Cor GB and BHG GS would be whored so much? Anyway, forgetting about the Supernova, fighters have absolutely crap anti-cap weaponry.. The Inferno and Mini-razor are all, and neither really does that much help.