Well on the general note of survey ships. You generally want them quite fast actually, faster than your main warships, and hopefully faster than ships you'll run across. Thats how they stay alive.
Might I point you to these designs that I use, pretty much every game I start, give or take a little bit in the design.
S-GEV-Chitose class Geosurvey Ship 6,000 tons 155 Crew 781.4 BP TCS 120 TH 600 EM 0
5000 km/s JR 3-50 Armour 1-29 Shields 0-0 Sensors 15/15/0/1 Damage Control Rating 8 PPV 0
Maint Life 4.53 Years MSP 651 AFR 36% IFR 0.5% 1YR 51 5YR 771 Max Repair 300 MSP
Intended Deployment Time: 6 months Spare Berths 1
Endoso-Matsuzawa J6000(3-50) Military Jump Drive Max Ship Size 6000 tons Distance 50k km Squadron Size 3
Raikatuji Space & Security 600 EP Ion Drive (1) Power 600 Fuel Use 40% Signature 600 Exp 10%
Fuel Capacity 1,000,000 Litres Range 75.0 billion km (173 days at full power)
Satoya & Asari Thermal Sensor TH2.5-15 (1) Sensitivity 15 Detect Sig Strength 1000: 15m km
Satoya & Asari EM Detection Sensor EM2.5-15 (1) Sensitivity 15 Detect Sig Strength 1000: 15m km
Geological Survey Sensors (1) 1 Survey Points Per Hour
This design is classed as a Military Vessel for maintenance purposes
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S-GSV-Chiyoda class Gravsurvey Ship 6,000 tons 155 Crew 781.4 BP TCS 120 TH 600 EM 0
5000 km/s JR 3-50 Armour 1-29 Shields 0-0 Sensors 15/15/1/0 Damage Control Rating 8 PPV 0
Maint Life 4.53 Years MSP 651 AFR 36% IFR 0.5% 1YR 51 5YR 771 Max Repair 300 MSP
Intended Deployment Time: 6 months Spare Berths 1
Endoso-Matsuzawa J6000(3-50) Military Jump Drive Max Ship Size 6000 tons Distance 50k km Squadron Size 3
Raikatuji Space & Security 600 EP Ion Drive (1) Power 600 Fuel Use 40% Signature 600 Exp 10%
Fuel Capacity 1,000,000 Litres Range 75.0 billion km (173 days at full power)
Satoya & Asari Thermal Sensor TH2.5-15 (1) Sensitivity 15 Detect Sig Strength 1000: 15m km
Satoya & Asari EM Detection Sensor EM2.5-15 (1) Sensitivity 15 Detect Sig Strength 1000: 15m km
Gravitational Survey Sensors (1) 1 Survey Points Per Hour
This design is classed as a Military Vessel for maintenance purposes
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S-TH-Akitsushima Mk1 class Scout 6,000 tons 155 Crew 711.4 BP TCS 120 TH 600 EM 0
5000 km/s JR 3-50 Armour 1-29 Shields 0-0 Sensors 60/1/0/0 Damage Control Rating 8 PPV 0
Maint Life 4.33 Years MSP 593 AFR 36% IFR 0.5% 1YR 51 5YR 764 Max Repair 300 MSP
Intended Deployment Time: 6 months Spare Berths 1
Endoso-Matsuzawa J6000(3-50) Military Jump Drive Max Ship Size 6000 tons Distance 50k km Squadron Size 3
Raikatuji Space & Security 600 EP Ion Drive (1) Power 600 Fuel Use 40% Signature 600 Exp 10%
Fuel Capacity 1,000,000 Litres Range 75.0 billion km (173 days at full power)
Thermal Sensor TH10-60 (1) Sensitivity 60 Detect Sig Strength 1000: 60m km
This design is classed as a Military Vessel for maintenance purposes
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S-EM-Mizuho Mk1 class Scout 6,000 tons 155 Crew 711.4 BP TCS 120 TH 600 EM 0
5000 km/s JR 3-50 Armour 1-29 Shields 0-0 Sensors 1/60/0/0 Damage Control Rating 8 PPV 0
Maint Life 4.33 Years MSP 593 AFR 36% IFR 0.5% 1YR 51 5YR 764 Max Repair 300 MSP
Intended Deployment Time: 6 months Spare Berths 1
Endoso-Matsuzawa J6000(3-50) Military Jump Drive Max Ship Size 6000 tons Distance 50k km Squadron Size 3
Raikatuji Space & Security 600 EP Ion Drive (1) Power 600 Fuel Use 40% Signature 600 Exp 10%
Fuel Capacity 1,000,000 Litres Range 75.0 billion km (173 days at full power)
EM Detection Sensor EM10-60 (1) Sensitivity 60 Detect Sig Strength 1000: 60m km
This design is classed as a Military Vessel for maintenance purposes
I might use other designs when putting about in Sol, with lower tech engines and no jump drives. But I try to make sure I can field something like these before I set foot outside of Sol. (also very regularly, picking a trans newtonian start can field these year 1)
All 4 designs use the same size 50 pwrmod 1 military engine. Which can be scaled to lower techs, the exact same engine combo on nuclear pulse will do 3333km/s i think.
And the jump drive requires jump efficiency 6 (usually TN start gives 5 or 6).
But forget about the technology in them. the single most important thing about these 4 designs.
If a navy yard is geared for producing either the geosurvey or gravsurvey ships, all 4 can be produced from the same yard without ever needing to retool.
Take the same design, scale the engines up a couple tech levels, and replace the sensors with newer more advanced ones, and you'll only need to retool 1 yard every once in a while to crap out all your passive scout ships.
Stripping all the passive sensors, with the same navy yard I can also produce a line of Active sensor support ships, as long as they don't exceed a size 5 active sensor (due to the higher uridium usage in active sensors. Heres 1 geared for spotting FACs.
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S-AG-Taigei class Scout 6,000 tons 145 Crew 757.8 BP TCS 120 TH 600 EM 0
5000 km/s JR 3-50 Armour 2-29 Shields 0-0 Sensors 1/1/0/0 Damage Control Rating 8 PPV 0
Maint Life 4.38 Years MSP 632 AFR 36% IFR 0.5% 1YR 53 5YR 795 Max Repair 300 MSP
Intended Deployment Time: 6 months Spare Berths 3
Endoso-Matsuzawa J6000(3-50) Military Jump Drive Max Ship Size 6000 tons Distance 50k km Squadron Size 3
Raikatuji Space & Security 600 EP Ion Drive (1) Power 600 Fuel Use 40% Signature 600 Exp 10%
Fuel Capacity 1,000,000 Litres Range 75.0 billion km (173 days at full power)
Active Search Sensor MR21-R20 (1) GPS 1600 Range 21.5m km Resolution 20
This design is classed as a Military Vessel for maintenance purposes
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Or even father in the list of "silly" things to do, is a small carrier for a couple early beam fighters, to frighten off any NPR scout ships
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CVL-Jun'you class Light Carrier 6,000 tons 140 Crew 685.4 BP TCS 120 TH 600 EM 0
5000 km/s JR 3-50 Armour 1-29 Shields 0-0 Sensors 1/1/0/0 Damage Control Rating 6 PPV 0
Maint Life 3 Years MSP 428 AFR 48% IFR 0.7% 1YR 71 5YR 1071 Max Repair 300 MSP
Intended Deployment Time: 6 months Flight Crew Berths 55
Hangar Deck Capacity 1000 tons
Endoso-Matsuzawa J6000(3-50) Military Jump Drive Max Ship Size 6000 tons Distance 50k km Squadron Size 3
Raikatuji Space & Security 600 EP Ion Drive (1) Power 600 Fuel Use 40% Signature 600 Exp 10%
Fuel Capacity 500,000 Litres Range 37.5 billion km (86 days at full power)
This design is classed as a Military Vessel for maintenance purposes
Ofcourse, should you copy these designs.
No. Actually they're turning out to be worse than I'd have liked. But the general concept is that in the early game, being able to turn out multiple ships for use in early exploration from the same yard can be an enormous money and time saver. Especially if 1 gets shot down, but you already shifted the yard over to produce something else, now you can't keep scouting till you turn it back and produce another ship. Also even though the 2 sensor ships aren't great (full military spotters would have sensor arrays in the size 50 range) They're cheap, and easily kept around, don't worry too much if 1 is lost because the yard is already geared to turn out another. And they're alright to leave on their own in a system to keep watch on an NPR.
As far as actually scouting.
The EM detector isn't so important of all of them, but you should have at least a couple, because they'll spot planets with colonies on them from significantly farther off than anything else. (for example, a planet with ~100m population will have ~2k for its thermal sig, but over 6k for its EM. The EM spotter will pick up this colony from 4x the range as the GEV and GSV ship's EM sensors. and 3x as far as the thermal will with its sensor) This will keep your scouts safer cause you can now avoid those planets, until you have something armed in system. Also wil help you pick up on what the target may be using for active sensors.
A thermal or 2 is kept around near either friendly survey ships, or known NPR colonies, because they'll pick up ships/thermal contacts from 4x the range as the surveyors. EM isn't so useful for this because not many ships will have shields, and most don't run around with their actives turned on.
Then for the GEV and GSV themselves. I usually like to have a lot of them. I like to pop into systems and have them fully scouted out within a month or so. 8-10 of each, they're cheap anyways.
Onto your other statements. Odds are what you ran across was either some
spoilerswhich would be ok. you say that they were going 3x faster than oyur military ships though. see this could also be just whatever given NPR, their FACs that a lot of them like to use for homeworld defense.
As far as setting 0 NPRs at start. Yes this will stop there from being any NPRs ingame until you actually leave sol, and go to a system that can generate them, and cause them to be generated. Good for having some time to get some techs before moving out. However remember, at 100% difficulty mod, newly generated NPRs will have similar tech to you (though probably kinda crap ship designs, they don't generally have very efficient designs)
Dunno about that max number of systems stuff. And building up a bit before branching out initially is generally a good plan.
For your edits.
Perhaps you could send in some dedicated scouts first before scanning a system, but I try and do both at the same time (hence the EM and Therm designs) since ifyou pull out all your scouts and just leave the surveyors in a normal game where there are NPRs starting with you, you can easily find yourself losing a bunch of surveyors while your scouts are off in a different system looking around.
EM sensor tech is used for 3 things: Passive EM sensors
Active Sensors (required for locking onto enemy ships to fire weapons. The EM portion of these however is tuned to work only with the resolution set for the active sensor though, so you can't use it to detect colonies and shielded ships passively like a regular passive EM sensor can)
Last, its a portion of missile fire controls, for the same reasons as it is part of active sensors (and well, they're both designed with the same menu)you need at least 1 of these on any ship thats going to fire a missile.
Edit in other news. I dunno how to use the forums properly