Too much engineering space on the ships, you want at least double the max repair figure, then only add more if you are aiming for a particular maintenance life. I tend to aim for 3 years so I don't need to resupply my ships between overhauls(overhauls rewind the clock at 3 times the time spent in overhaul, so 3 years service 1 year overhaul works out nicely).
Armour is much better now, however one thing you should note, enemies love to target your sensor ships, as the massive em emissions when their sensors are activated make them prime targets. As such you may want to put more armour onto your sensor ships.
Your missiles have too much range for your tech-level. Drop it by half on your ASM's and put the space into warhead or engines. Drop it down to around 3 million km for your AMM's and put the space into engines and agility. Adapt your active sensors and fire controls to match.
If you are facing an enemy that uses large numbers of ships midway between the standard sensors it can be worthwhile designing a specific sensor to pick them up, eg if facing large numbers of 3000 ton ships a res 60 sensor may be worth the investment.
Your cruiser needs some more tonnage in engines, it is going to be slowing down the rest of the taskgroup. I'd add another 4 engines and boost the cruiser up to 15,000 tons with other systems such as a second fire control and additional launchers.
You will definitely want to add a tanker to your taskgroup as your over-charged engines are going to burn through fuel fast.
Consider researching the reduced size launcher techline. Salvo size tends to be the most important aspect of getting missiles through point defence screens, unless your fire rate is comparable to their point defence/AMM rate. 50% size launcher tend to be the best balance for general use in ASM's coupled with a set of 2-3 times the number of box launchers to give a large alpha strike capability.
2) IMHO Resolution 40 fire controls/sensors are a bad compromise unless you're actually facing HS40 ships (2000 tons), their actual ranges against the more formidable 5000+ ton ships will be MUCH less than the listed range, so you'll be wasting a lot of the potential range of your missiles.
That's wrong. Anything of at least 2000 tons will show up at the listed ranges on the sensor ships active sensor. It is only if the target is below the listed resolution that you see a reduction in detection range.
Still, I'll agree that resolution 40 is not a good compromise spot, it is too large to get any reasonable detection on FAC's or fighters while not really being efficient for detecting large ships.
Typical resolutions I will use are;
Res 1 for detecting missiles and close fighters. As missile size 6 missiles will only get detected at 1/9th the listed range, aim for a range of 18-20 million km giving a missile detection range of 2 million km. At low tech levels you are unlikely to be able to do better without enormous sensors.
Res 10 for picking up fighters at longer distances. - This is the one that most often gets skipped if space need to be saved, the overlap between res 1 and FAC sensors can make it unneeded.
Res 20 for picking up FAC's. - Or Res 16 if expecting one of the spoiler races.
Res 100 for picking up ships below light-destroyer size.
Res 500 for picking up any real ships.