Torpedoes are UNNAFECTED by power setup (firing at minimum weapon power lvl will cause as much damage as firing at max weapon power lvl). Don't remember were i read it, and it empirically seems it is the case as far as i can tell ( currently running a T3 missile boat/broadside beam sci ship and being a "rear torpedo" guy since T1 - I alway loved burst damage in MMOs, but thats another story - ).
I also noticed that range doesnt seems to affect the torpedo damage. It seems that torpedos miss as often at long range than at short range, and torpedoes DO miss often: make me bump on the thread that the "accuracy" stat of a weap (wich is currently hidden to us) seems to be very important for a torpedo launcher, but i didnt make any tests about this last statement yet...
I think the only torpedo thats effected by range is the high yield plasma, the rest do normal damage no matter what the range (at least within the 10km firing range)
Cant really tell since torpedo damage vary from each torpedoes in a wide range, even in a salvo.
I suspect torpedoes having best effiency at around 6-7km but i'm really not sure about this since the damage of a given torpedo varies so much, and thats usually when the ennemy shield have melt from my alpha tachyon beam strike.
However im pretty sure that torpedoes can hit as harder at close combat range than max range. I think the 6-7km optimal range i've noticed is due to my opening move rather than anything else.
But i would like to see some analyzis depending on Disruptor, Plasma and Phaser Beams and the different damage they would probably does depending the range!
I readed some weeks in the past, that Disruptor Beams for example, suffer a greater range penalty as Phasers!!! I would like to see whether your testing would prove that or not
I haven't fully tested this yet, but based on some playing around with what weapons I had laying around, the damage type (phaser, disruptor, etc) of energy weapons made no difference to the effects of range.
It's on my list to test further, and I'll update the article when I do.