MIRVs are good if you have missile skills but the conquest doesn't really have the OP to put ECCM on it and MIRVS are a huge OP drain in and of themselves. Plus you ideally have both ECCM and missile skills to make MIRVs really good
I think that a missile support conquest is entirely valid. But its not so much better than a Gryphon that i would consider using it in that way unless you were starved for that kind of ship
Buuuuuut
Dual Gauss, Ion Beam(or whatever), 1 dual flack, 3 Tac Laser(forward side), 5 Burst PD(rearward side), 2 MIRV, 2 Harpoon, ECCM, EMR, ITU, ATG is a legit ship if you have missile skills
Its just a bit hard to put together because the Gauss are hard to come by and you NEED missile skills to make the MIRVS good.(when you have them though they're effectively 3000 range guided reapers)
Squalls are bad. They're a brawling support weapon that doesn't burst against enemies that like to run away and burn your missiles anyway. Sabots are superior. Only exception is on ships that WANT to keep enemies away rather than fight them. So its fine on the Astral
Re: Gauss and Mark IX. Yes but Gauss have perfect accuracy, no recoil, and 1200 range. Plus they do 700 damage/shot so even after kinetic damage reduction vs armor they have effective armor piercing.
You can say that Mark IX have more range than Storm Needlers but... i find that is not the case in the majority of situations. Just as Arbalests do not end up having less effective range than heavy auto-cannons. If killing frigates ever stopped becoming valuable then maybe there would be a point to Mark IX's... but it doesn't stop being so AND storm needlers do so much more efficient dps anyway.
Its just a bit hard to put together because the Gauss are hard to come by