1) Back to 4 large missile slots
2) Remove the special ship flag that lets its missile slots turn (in retrospect, that's a no-brainer to rein in any Cyclone concerns, the ship *has a special flag* that makes these an issue in the first place)
3) Shield efficiency to 0.8, the midline standard (Not sure if the Executor should be affected here, too or not - my impression is that the Executor is in a good place right now)
4) Movement speed to 35 (the Executor keeps it 50 and gets larger engine glows)
5) Possibly DP to 60; not sure if that's needed or not
At least, that's what I'm thinking at the moment. Could very well change, I'm not settled on any of it.
Executor larger engine glows, I'm all for this oh yes.
I think the executor could be nerfed to 0.8 shield efficiency, but be given a higher flux capacity as a result. This way weapons like autopulse fit better on it, at the cost of capacitors being less effective use of OP on the executor. Overall I think it would be a nerf, and the executor seems good enough to be able to 'afford' a nice little nerf. I agree that the executor really should keep its current speed though, and that the executor is largely in a good place. It's probably imbalanced in that it has access to HEF on 2 large energies which the player can abuse like nuts, but that never stopped the Doom from staying in its current form despite being exceptionally powerful in player hands, right? Hehe.
As far as the Pegasus goes, on top of the nerfs it currently has planned to make room for the 4 large missiles, you could try also giving it a smaller shield arc, say 120 degrees. This would keep its battleship identity, but introduce a new weakness to help accomodate the power of the 4 missile slots + FMR.