To further expound on the maintenance comment: While 21% is a good low number, take a second look at the amount of supplies vs the max repair cost. 2400+ supplies, 80 max. This means that the biggest item on your ship can break down 30 times before you run out of supplies. That's excessive. This means you can trim back on the amount of supplies, to free room for other systems.
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The beam weapons you have aren't turret mounted, and therefor have a tracking speed equal to your ship current top speed. They are really too slow to be used for anti-missile work, and between the (relatively) thin armor and slow speed, you aren't likely to get into close range with anything slow enough to effective hit with the lasers. Your ranges (missile range/MFC range/ASS range) are odd. Your MFC has a larger range than your ASS, that's backward. Having a MFC with a longer range than your missile's range isn't a bad thing, but unless you are futureproofing, the range difference is greater than you need. And of course you already know about the missing BFC.
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Basically, ship design comes down to fleet doctrine. What's yours? Mine is illustrated below, its a viable one, but obviously not the only one.
At higher tech levels you can get away with '1 size fits all' generalist approaches, but at lower tech levels you are probably (IMNSHO) better off with a 'one role per ship approach', specializing. My fleet core element is made of three classes of ships:
* A fleet scout (big active sensors, large thermal sensors)
* a missile boat (large magazines, backup active sensor, one type of launcher designed to throw anti-ship missiles)
* a point defense boat (either AMMs (make sure you have large magazines)) or beams (shorter ranged, need high tracking speed beam fire controls and weapons), and a powerful sensor designed to detect missiles at a useful engagement range, which your current resolution 100 sensor won't).
Once you get a viable design for those three ships, then you can apply what you learned to a multirole design if you want. I make two kinds of replenishment ships - one as a collier (you will be appalled at the amount of missiles you use, make more) and one as a fuel tanker&maintenance supplies ship. Having a supply of spare parts & fuel lets you trim down the amount carried on the ships going into harm's way, which lets you stick in more weapons and defense, etc.
A sample to illustrate, these designs a little more advanced than what you gave as an example:
Missile bombardment boat, the S1 SBM is the submunition (2 of them) the S5 bus releases once its slowly made its way near the target. Current bombardment doctrine is 'The biggest salvo possible', to get past some pretty impressive NPR anti-missile defenses. Sure, its a long time between salvos, but they are big salvos. The active sensor is a backup, never used, since the fleet scout carries a bigger one:
AD1 Cheveldi class Destroyer 6,000 tons 450 Crew 1213.75 BP TCS 120 TH 300 EM 0
3333 km/s Armour 10-29 Shields 0-0 Sensors 56/1/0/0 Damage Control Rating 7 PPV 21.25
Annual Failure Rate: 41% IFR: 0.6% Maint Capacity 885 MSP Max Repair 91 MSP Est Time: 6.38 Years
Magazine 357
Magneto-plasma Drive E6 (5) Power 80 Fuel Use 60% Signature 60 Armour 0 Exp 5%
Fuel Capacity 200,000 Litres Range 100.0 billion km (347 days at full power)
Size 5 Missile Launcher (25% Reduction) (17) Missile Size 5 Rate of Fire 3750
MFC ASM 151mkm (1) Range 151.2m km Resolution 100
SBM S1g2 W4 r4.8mkm (1) Speed: 30,900 km/s End: 2.6m Range: 4.8m km WH: 4 Size: 1 TH: 185 / 111 / 55
ASM S5g2 W4 sW4x2 r132mkm s2.5mkm (70) Speed: 16,000 km/s End: 140.6m Range: 137.5m km WH: 1 Size: 5 TH: 53 / 32 / 16
Active Search Sensor MR100-R100 (1) GPS 9100 Range 100.1m km Resolution 100
Thermal Sensor TH4-56 (1) Sensitivity 56 Detect Sig Strength 1000: 56m km
MicroEM Detection Sensor EM0.1-1.1 (1) Sensitivity 1.1 Detect Sig Strength 1000: 1.1m km
ECCM-2 (1) ECM 20
Missile to hit chances are vs targets moving at 3000 km/s, 5000 km/s and 10,000 km/s
This design is classed as a Military Vessel for maintenance purposes
Fleet scout, why yes, that is a big sensor:
AD1 Palantir class Destroyer Escort 6,000 tons 531 Crew 1749 BP TCS 120 TH 300 EM 0
3333 km/s Armour 10-29 Shields 0-0 Sensors 56/1/0/0 Damage Control Rating 7 PPV 9
Annual Failure Rate: 38% IFR: 0.5% Maint Capacity 1366 MSP Max Repair 720 MSP Est Time: 2.65 Years
Magazine 217
Magneto-plasma Drive E6 (5) Power 80 Fuel Use 60% Signature 60 Armour 0 Exp 5%
Fuel Capacity 220,000 Litres Range 110.0 billion km (381 days at full power)
Size 1 Missile Launcher - AMM (9) Missile Size 1 Rate of Fire 10
MFC AMM 2.3mkm (1) Range 21.2m km Resolution 1
AMM S1g2 r3.6mkm (217) Speed: 45,900 km/s End: 1.3m Range: 3.6m km WH: 1 Size: 1 TH: 459 / 275 / 137
ASS S1008mkm G40mkm F2.5mkm (1) GPS 72000 Range 1,008.0m km Resolution 100
Thermal Sensor TH4-56 (1) Sensitivity 56 Detect Sig Strength 1000: 56m km
MicroEM Detection Sensor EM0.1-1.1 (1) Sensitivity 1.1 Detect Sig Strength 1000: 1.1m km
Compact ECCM-1 (1) ECM 20
Missile to hit chances are vs targets moving at 3000 km/s, 5000 km/s and 10,000 km/s
This design is classed as a Military Vessel for maintenance purposes
AMM Boat:
AD1 Overwatch class Destroyer Escort 6,000 tons 575 Crew 1312 BP TCS 120 TH 300 EM 0
3333 km/s Armour 7-29 Shields 0-0 Sensors 1/1/0/0 Damage Control Rating 7 PPV 18
Annual Failure Rate: 41% IFR: 0.6% Maint Capacity 957 MSP Max Repair 216 MSP Est Time: 4.15 Years
Magazine 482
Magneto-plasma Drive E6 (5) Power 80 Fuel Use 60% Signature 60 Armour 0 Exp 5%
Fuel Capacity 210,000 Litres Range 105.0 billion km (364 days at full power)
Size 1 Missile Launcher - AMM (18) Missile Size 1 Rate of Fire 10
MFC AMM 2.3mkm (2) Range 21.2m km Resolution 1
AMM S1g2 r3.6mkm (482) Speed: 45,900 km/s End: 1.3m Range: 3.6m km WH: 1 Size: 1 TH: 459 / 275 / 137
ASS AMM 3.2mkm (1) GPS 216 Range 30.2m km Resolution 1
Compact ECCM-1 (2) ECM 20
Missile to hit chances are vs targets moving at 3000 km/s, 5000 km/s and 10,000 km/s
This design is classed as a Military Vessel for maintenance purposes
I could probably trim back the amount of fuel, but that's what I'm currently running. Not shown are the collier, replenishment ship, small craft tender (to support the gunboat operations, and the new fleet strike fighters), or the jump destroyers used to get the fleet from system to system.