I've been thinking along these lines as well. I want the plasma torpedoes in RA to be a little closer to the ones in Federation Commander in terms of their damage profile. In FC a seeking torpedo typically has the potential to do around 2.5x the damage as a bolted torpedo, whereas in RA the Bolt will statistically do about 1.33x more damage than the seeking torpedo. I'd like to reverse the RA situation and make the seeking torpedo a weapon worth taking seriously.
Here are a few of my thoughts
1) All Plasma Torpedoes move Speed 9 (in FC they are all the same speed - the smaller ones just run out of damage sooner).
2) Instead of the diminishing to hit number, Plasma Torpedoes get a new Fighter Trait: Diminishing Size -2. Diminishing as a general trait could have value of -1, -2, or -3. In the Fighter Phase, any Torpedo that doesn't make an attack has it's Size reduced by the listed amount. In the case of RA Torps, an S-Torp for instance would be Size 5 if it impacts on turn 1, but if not would be Diminished and would be a size 3 torp in the next turn, etc. A Torpedo that is diminished to size 0 is removed. This reduction scheme results in Torpedo ranges/durations fairly consistent with those in FC.
3) If you are basing the seeker characteristics off of the Bolt profile, then make the Torpedo Starting Size = to the Bolt Imp x Dam or some similar formula.
4) Seeking Plasma Torpedoes should be Damage 2.
5) In a perfect world I'd like to balance the enhanced seeker with a less imposing bolt so that the whole thing is close enough to the same overall effectiveness that I don't have to repoint every Romulan ship. The original seeker was of such limited utility compared to the bolt that it essentially didn't count, but an enhanced seeker certainly does...So for instance, The plasma S torpedoes might look something like this...
Plasma S - Bolt Rng: 5/10/15 ROF: 1 ACC: 4+ IMP: 2 DAM: 3 Slow Firing
Plsma S - Seeker Size 5, Speed 9, ACC: 4+, DAM 2 Diminishing Size -2Brian
I like where you are going with this Brian. The diminishing size thing is a great way to simulate the reduced effectiveness of the plasma torps as they travel for longer - and it also makes them easier to finish off with phasers after they have travelled a bit.
I can see coming up with a cost getting quite complicated and/or subjective.
What I think could be an elegant solution (and one that would add something to starmada) is to introduce a brand new weapon type called a seeker launcher. This weapon would have an arch and unlimited ammo by default (although you could use the ammo trait). It would be able to launch one flight of seekers per turn at a target in its arch. The seekers would in all ways function like normal seekers. This seeker launcher would not require carrier space or interact in anyway with the launch rate of the ship.
The cost of a seeker launcher would have to be based on the cost of the seeker flights that it launched, modified by any other traits on the weapon itself (like slow firing, #arcs, ammo, and whatever else is appropriate).
THEN, plasma launchers in RA could be dual mode weapons with a direct fire bolt portion and a seeker launcher in the other mode.