@ Plantissue: As far as I know, there is only one MIRV in unmodded game, the Hurricane MIRV.
Locusts as anti-armor? Against small targets like destroyers and smaller, damage is overwhelming enough that it does not matter. Big targets, no argument they are not very effective, but as I wrote before they are good against hull. The ships (I use) that can make good use of Locusts also have other ways to punch holes in armor. Apogee? Its large energy weapon (or Mining Blaster during early game). Conquest? It has a bunch of ballistics to choose from. I rarely use Gryphon, and using missiles instead of fighters on Astral is silly. If I use Legion (XIV), it is mainly to give Hammer Barrage or Cyclone Reaper some love, so no Locusts or Hurricanes on that (even if they may be better). Odyssey has ECCM for free, so it is a good candidate for MIRVs, if I can squeeze Expanded Missile Racks on it. (I probably would eschew missiles if I attempt dual plasma loadout, though.)
I often use PD without IPDAI, although if I am stuck with normal PD Laser or LR PD, I do use IPDAI. I do not remember using IPDAI with any ballistic PD, except (rarely) on Railguns. For energy, continuous beam PD is anemic, and almost need it (if pilot does not have Advanced Countermeasures 3).
Advanced Optics has that turn speed penalty which may necessitate Advanced Gyro Turrets. I do not use Advanced Optics very often. (Also, while I would like Advanced Optics for four lance Paragon, getting that means giving up Hardened Shields.)
Hurricane is worthwhile without ECCM.
I only agree with this if the pilot has missile spec. Otherwise, unboosted submunitions do not converge enough and too many of them miss against most targets. The few that do hit do not cause enough damage to make MIRVs worthwhile, unless there are no better options. If the ship needs to hang back from long range and snipe with Gauss Cannons and MIRVs, then sure, that loadout needs MIRVs. (In such a case, I probably want an officer with Missile Spec. so that the MIRVs will converge and hit smaller stuff more easily.)