I enjoyed reading the OP but the main point, as well as the relevance to the game generally, are suspect. Multicannons LOOK wrong for their sound and ROF, and their power draw is merely a balancing factor. If you want an example of a strangely high power draw, look at Dumfire missile racks; nearly as much as a beam laser! What are they doing, manufacturing the propellant as you fly around?
The weapons are that way purely for balance. When dumbfires get their damage nerf maybe FD will see their way to dropping the power draw a bit in compensation. Way back before Beta-1 there was a dev quote (from MB i think) going around about E: D being a game that "slapped realism in the face" or "hit it with a stick" or somesuch. Here is my take on realistic future space warfare:
1) Instruct computer to initiate combat 2) Await outcome.
Sounds fun, eh?