No, No, Maybe, No.
Big, nasty death ships don't work in FS2. The fighter is, and always will be, the ultimate, ultimate weapon, because it's a fighter simulator, and, even if you're interested primarily in the universe (rather than the game, from a useful to mission design POV), that fighter centricity leaks over into the canon - consider The final mission of FS1, the Hammer and the Anvil, Slaying Ravana, Bearbaiting, Rebel Intercept, and... err, that one with the Mjolnirs when you're covering the node against the NTF using...Artemises I think (unless that is RI) - canonical points where fighters own capships.
So, from the point of view of the universe, and from the point of view of making fun missions, fighter related ships should be the most important. What you're proposing are capships designed to kill capships, and that's just not where GTVA ship design has to go. Consider the Shivan Threats -
Lucifer - They seemed pretty confident the Collossus' beams could kill it. If beams can kill it, then you can use Corvettes, or specially designed single BFGreen Emitter ships. If not, then you'rte forced to use nodes and bombers to kill it anyway.
Demon - Hardly a threat - kill with bombers.
Ravana - Dangerous to capships, taken out by a single bombing run.
Sathanas - Definitely a danger, and too big for bombers alone to take out, but can be destroyed by sustained conventional fire if bombers take out the four main claw guns ala bearbaiting.
Fighters and Bombers - dangerous, be can be dealt with in the traditional manner (i.e. friendly fighters)
The key element? Every Shivan ship can be dealt with, if bombers, fighters and ordinance is made available. Ships related to fighters, either carriers designed to ferry them around, or small ships designedc with fighter defence in mind are the way forward for the GTVA. Hmmmm... I should write some of this down...