You said they won't die during the 15 seconds RSP is up. And no, of course they won't. If there was a weapon that could blow through a ship in 15 seconds right through the shields, it would be the only weapon anyone ever used.
And rapid fire + quantums won't blow them away through RSP either, but at least transphasics would do SOME damage through it. Which is what they're supposed to?
Actualy, you can disable shield system in 4s, and torpedo the target in next 6s...and i have killed many people under 10s...so there already is a way :p
I've been toying with a Transphasic Torpedo ship tonight. Not decked out in the best of gear nor the best ship class for it (IMO) since I'm only at BG2.
* Using a Negvhar
* 2 Transphasic Torps Forward (Class 8 & 10) / 1 Class 8 Quantum Torp Aft
* Cannons: 1 Disruptor Cannon Fwd / 1 Hvy Dual Disruptor Cannon Fwd / 2 Disruptor Turrets (All Class X whites)
* With the Negvhar, I can have a Tac BOff that can use only up to Tier 2 abilities, so it is limiting. I got one of my newer Tac BOffs with HYT 1 & 2
With a Torpedo heavy build, Cannons aren't my focus, TBH. Torpedoes are. I dump more power to the other 3 areas and not have to dump so much into Weapons, since Torpedo tubes aren't dependent on Weapon power for damage effectiveness (correct me if I'm wrong). I can have for instance higher Aux power, so some nifty Engineering skills get a very nice boost.
In a Team environment of PvP, my priority targets are Science and Escorts, or Cruisers that are weakened and need to be finished off. Target priority are Escorts > Science > Weakened Cruisers. Target shields may be up and running and getting buffed by friends, but the fact that some damage is bleeding through due to Transphasics adds extra pressure on the opposition to keep that ship alive. Cruisers... unless the player is a newbie or are low on hull, I don't go for them with Transphasic Torps. Or the fun Escort / BoP ploy of going after Science ships that are well underway in keeping other ships alive.
The Torpedo ship can work IMO but feels a bit clumsy due to the shared tube cooldowns. It can work across all ship types but would feel alot better on Escorts / BoPs. Contemplating on getting a BoP or Raptor and giving it a whirl, especially liberal use of Tactical BOff abilities. Still, Cruisers like a Vor'Cha or Negvhar can do this build. Not as offensively potent as the Escort / BoP based torpedo builds, but you can boost up other system power to improve skills based on them, is a nice boost to your team in repairs / buffs, while still dishing out hurt with torpedoes. The Cruiser based torpedo build would of course be best at medium-long range fights (>5k range) since they have a tighter weapon arc for their primary weapons.
Do people normally pop RSP at full health? Just because you can't be arsed to actually comprehend what you read and then concluded I meant 100-0 in 15s is exactly what I wanted isn't my fault.
Transphasic torpedos have no purpose whatsoever currently. The damage they do to the hull gets repaired by BOPs pretty easily, much less cruisers.
edit: and as I noted, and many others have, 15s is WAY longer than it normally takes to kill someone anyway, so the original "point" which relied on a comprehension failure doesn't even make sense in any way.