Alright, here's my initial proposal.
Rationally, this is intended to be our mothership for a long while, the intention is to be a long-range sniper HQ, taking potshots at enemy forces from a relatively safe distance while we engage with our more expendable forces. Essentially like the mothership in Homeworld 2 after they get Sajuuk, just more effective in some ways.
This means a focus on being the core of a fight, heavy emphasis on long-range E-war, teleportation, and disabling ships from the inside after knocking out their shields.
As an aside, high maneuvering thrusters is kinda dumb imo on this scale of ship. It's slow and huge as fuck, I seriously doubt the viability or worth of it.
[] Plan: Mothership Draft
-[] Reference Image
-[] Hull: Grand Cruiser (12,000 BP, -500 CP)
-[] Engines: 2.5 Gravities (1100 BP)
-[] Shields: Medium (800 BP)
-[] Armor: Medium (800 BP)
-[] Empty hull cost: 12,000 + 1100 + 800 + 800 + 2,500 (No Shipyard Tax) = 17200, Budget for filling the hull is 12000 BP.
-[] Non-Combat Equipment (Does not contribute to Cramming)
--[] Warp Drive (1,200 BP)
--[] Warp Abacus Mounting (600 BP)
--[] Psychic Shielding (2,400 BP)
---[] Hull + Non-Combat Equipment Cost: 21400 BP
-[] Weapons:
--[] 2x Heavy Lances (800 BP)
--[] 4x Medium Lances (800 BP)
--[] 2x Medium Plasma Cannon (1000 BP)
--[] Heavy Plasma Cannon (1000 BP)
--[] 12x Point Defense (600 BP)
--[] 2x Shuttles (200 BP, -100 CP)
--[] 1x Assault Shuttle (150 BP, -50 CP)
--[] Heavy Teleportarium (400 BP)
---[] Total running cost: 21400 + 4950 = 26350 (4950 BP weapon cost, 4455 size cost, 7545 BP left of space budget)
-[] Combat Equipment:
--[] Heavy Machine Spirit Jammers (2400 BP)
--[] Plasma Macrocannon warheads (600 BP)
--[] Medium Boarding Preparations (1200 BP)
---[] Total running cost 26350 + 2400 + 600 + 1200 = 30550 BP (7545 BP of space budget - 2400 BP - 600 BP - 1200 BP = 3345 BP of space budget)
--[] Installations: 3345 leftover BP means 33 modular build slots.
--[] 15x manufactories for (1500 BP, -750 CP)
--[] 1x Observatory (100 BP, -25 CP)
--[] 1x Basic Biology Research Lab (50 BP, -50 CP)
--[] 1x Basic Technological Research lab (50 BP, -50 CP)
--[] 1x Captive Holding cells (25 BP, -10 CP)
--[] 1x Juvenat production facility (250 BP, -50 CP)
--[] 1x Crew Quarters (50 BP, -15 CP)
--[] 10x Troop compartment (25 BP, -5 CP)
--[] 2 Empty modular slots (free)
---[] GRAND TOTAL: 26350 + 2275 BP = 28625 BP
This would be easier with a spreadsheet, in truth. I might whip one up just to streamline the process the next time I try my hand at shipmaking. Much easier to tweak things that way, and far less error prone.
Combine that with Swarm Missile Networks (having missile datanet to coordinate strikes independently for maximum effect against single or multiple targets), and even a Phalanx would be filleted with enough missile swarms.
Sounds like a lot of words when what you really just want is an Itano Circus. Or Macross Missile Massacre if you prefer that term.