Your original designs

[Iranon]

Yes, much too thirsty.

Take the Jumper Stealth:
4x 0.8 power engines and 100HS fuel fits on the same tonnage, has the same speed, uses 18% as much fuel, and has several times the range.

4x1.2 power engines and 100HS fuel has slightly more range than the original, uses 49% as much fuel, and is 50% faster.

Overstressed engines compensated by excessive fuel load is the easiest way to ruin a design. Even if you want the design to refuel others, it's too much.

[Barkhorn]

You've got practically no missile defense.  Also your fire control's speed doesn't match your turrets' tracking speed.

[littleWolf]

new modification Jumper with new engines, pd turrets, sensors & etc. some fuel need to refuel explorers-fighters squadron on Scout-Stealth in long expedition. 

Jumper Stealth - mk7 class Jump Escort Cruiser    30 000 tons     662 Crew     11101.5 BP      TCS 60  TH 240  EM 0
3333 km/s    JR 3-50     Armour 2-86     Shields 0-0     Sensors 900/2/0/0     Damage Control Rating 31     PPV 41.4
Maint Life 0.04 Years     MSP 3231    AFR 7200%    IFR 100%    1YR 87833    5YR 1317488    Max Repair 5000 MSP
Intended Deployment Time: 100 months    Spare Berths 0   

J30000(3-50) Military Jump Drive     Max Ship Size 30000 tons    Distance 50k km     Squadron Size 3
1000 EP Inertial Fusion Drive TR12 FC25 EP1.25 (2)    Power 1000    Fuel Use 32.75%    Signature 120    Exp 12%
Fuel Capacity 10 000 000 Litres    Range 183.2 billion km   (636 days at full power)

Twin R9/C3 Meson Cannon PD  r90 Turret (5x2)    Range 90 000km     TS: 40000 km/s     Power 6-6     RM 9    ROF 5        1 1 1 1 1 1 1 1 1 0
Fire Control S02 100-25000 H70 pd (1)    Max Range: 200 000 km   TS: 25000 km/s     95 90 85 80 75 70 65 60 55 50
Solid-core Anti-matter Power Plant  P32 (1)     Total Power Output 32    Armour 0    Exp 5%

Active Search Sensor MR8-R1 (70%) ams (1)     GPS 48     Range 8.6m km    MCR 941k km    Resolution 1
Thermal Sensor TH50-900 (70%) (1)     Sensitivity 900     Detect Sig Strength 1000:  900m km
EM Detection Sensor EM0.1-1.8 (70%) (1)     Sensitivity 1.8     Detect Sig Strength 1000:  1.8m km
Cloaking Device: Class cross-section reduced to 10% of normal

This design is classed as a Military Vessel for maintenance purposes

My millitary FAST fleet:

(maybe need replace 5x2 meson pd turrets  on EWC and JD  to 3x2 gauss pd turrets. Meson pd better vs heavy armored missile, but Gauss pd - vs swarms of small fast missile)

1 Sentry ship 

Sentry class Early Warning Craft    10 000 tons     302 Crew     6474.5 BP      TCS 200  TH 360  EM 0
15000 km/s     Armour 3-41     Shields 0-0     Sensors 1/1/0/0     Damage Control Rating 0     PPV 41.4
Maint Life 0 Years     MSP 0    AFR 2000%    IFR 27.8%    1YR 13705    5YR 205578    Max Repair 1500 MSP
Intended Deployment Time: 30 months    Spare Berths 0   

1000 EP Inertial Fusion Drive TR12 FC25 EP1.25 (3)    Power 1000    Fuel Use 32.75%    Signature 120    Exp 12%
Fuel Capacity 1 250 000 Litres    Range 68.7 billion km   (53 days at full power)

Twin R9/C3 Meson Cannon PD  r90 Turret (5x2)    Range 90 000km     TS: 40000 km/s     Power 6-6     RM 9    ROF 5        1 1 1 1 1 1 1 1 1 0
Fire Control S02 100-25000 H70 pd (1)    Max Range: 200 000 km   TS: 25000 km/s     95 90 85 80 75 70 65 60 55 50
Solid-core Anti-matter Power Plant  P32 (1)     Total Power Output 32    Armour 0    Exp 5%

Active Search Sensor MR2160-R100 (70%) (1)     GPS 120000     Range 2 160.0m km    Resolution 100
Active Search Sensor MR8-R1 (70%) ams (1)     GPS 48     Range 8.6m km    MCR 941k km    Resolution 1
Thermal Sensor TH0.2-1 (1)     Sensitivity 1     Detect Sig Strength 1000:  1m km
EM Detection Sensor EM0.2-1 (1)     Sensitivity 1     Detect Sig Strength 1000:  1m km

This design is classed as a Military Vessel for maintenance purposes

1 jumpship:

Jumper class Jump Destroyer    10 000 tons     309 Crew     5035.5 BP      TCS 200  TH 360  EM 0
15000 km/s    JR 6-50     Armour 2-41     Shields 0-0     Sensors 1/1/0/0     Damage Control Rating 1     PPV 41.4
Maint Life 0.08 Years     MSP 315    AFR 800%    IFR 11.1%    1YR 4013    5YR 60198    Max Repair 1250 MSP
Intended Deployment Time: 30 months    Spare Berths 1   

J10000(6-50) Military Jump Drive     Max Ship Size 10000 tons    Distance 50k km     Squadron Size 6
1000 EP Inertial Fusion Drive TR12 FC25 EP1.25 (3)    Power 1000    Fuel Use 32.75%    Signature 120    Exp 12%
Fuel Capacity 1 250 000 Litres    Range 68.7 billion km   (53 days at full power)

Twin R9/C3 Meson Cannon PD  r90 Turret (5x2)    Range 90 000km     TS: 40000 km/s     Power 6-6     RM 9    ROF 5        1 1 1 1 1 1 1 1 1 0
Fire Control S02 100-25000 H70 pd (1)    Max Range: 200 000 km   TS: 25000 km/s     95 90 85 80 75 70 65 60 55 50
Solid-core Anti-matter Power Plant  P32 (1)     Total Power Output 32    Armour 0    Exp 5%

Active Search Sensor MR8-R1 (70%) ams (1)     GPS 48     Range 8.6m km    MCR 941k km    Resolution 1
Thermal Sensor TH0.2-1 (1)     Sensitivity 1     Detect Sig Strength 1000:  1m km
EM Detection Sensor EM0.2-1 (1)     Sensitivity 1     Detect Sig Strength 1000:  1m km

This design is classed as a Military Vessel for maintenance purposes

4-5 destroyers

Grom class Destroyer    10 000 tons     311 Crew     7873 BP      TCS 200  TH 360  EM 0
15000 km/s     Armour 4-41     Shields 0-0     Sensors 1/1/0/0     Damage Control Rating 1     PPV 48.56
Maint Life 0.1 Years     MSP 492    AFR 800%    IFR 11.1%    1YR 4943    5YR 74147    Max Repair 1875 MSP
Intended Deployment Time: 30 months    Spare Berths 1   

1000 EP Inertial Fusion Drive TR12 FC25 EP1.25 (3)    Power 1000    Fuel Use 32.75%    Signature 120    Exp 12%
Fuel Capacity 1 250 000 Litres    Range 68.7 billion km   (53 days at full power)

25cm C8 X-Ray Laser ROF2 PR8 R1.1m (4)    Range 800 000km     TS: 15000 km/s     Power 16-8     RM 7    ROF 10        16 16 16 16 16 16 16 13 12 11
Twin R9/C3 Meson Cannon PD  r90 Turret (2x2)    Range 90 000km     TS: 40000 km/s     Power 6-6     RM 9    ROF 5        1 1 1 1 1 1 1 1 1 0
Fire Control S08 400-25000 H70 (1)    Max Range: 800 000 km   TS: 25000 km/s     99 98 96 95 94 92 91 90 89 88
Fire Control S02 100-25000 H70 pd (1)    Max Range: 200 000 km   TS: 25000 km/s     95 90 85 80 75 70 65 60 55 50
Solid-core Anti-matter Power Plant  P32 (2)     Total Power Output 64    Armour 0    Exp 5%

Active Search Sensor MR8-R1 (70%) ams (1)     GPS 48     Range 8.6m km    MCR 941k km    Resolution 1
Thermal Sensor TH0.2-1 (1)     Sensitivity 1     Detect Sig Strength 1000:  1m km
EM Detection Sensor EM0.2-1 (1)     Sensitivity 1     Detect Sig Strength 1000:  1m km

ECM 40

This design is classed as a Military Vessel for maintenance purposes