It's a good beginner design, and I don't see any critical flaws in it which will render it inoperable. That said, there are a few ways you can improve on it.
From top to bottom:
1. The DCR tells me you're using damage control, which weighs down the ship by good 150 tons without providing much benefit (lack of armor and shields will ensure it dies before making use of its damage control, and instant repairs will quickly run into lack of MSP). This weight is better used in more engineering, fuel, and deployment time.
1. 1. On topic of engineering, I'd recommend having at least twice as much MSP as Max Repair, to allow for on-board repairs of the most expensive part of your ship. Max Repair lists the cost of maintaining such part; repairs will require double.
2. Cryo berths also weigh it down a little, but I presume they're there for RP reasons. If they aren't, they can safely be removed; since the boat will be patrolling between populated colonies, there'll always be one close by to drop survivors and POWs.
3. The deployment time could be a little higher.
4. This ship is slow by the Quantum Singularity standards. If it's meant to move around escorting commercial ships, it's fine, and low-boost engines also makes the patrol ship very cheap; but keep in mind that at this tech level it's easy to push 50kkm/s or more.
5. The only thing in terms of defense this ship has is its ECM suite and range of its missiles. 5 points of shield is not stopping anything, and even if they did, you're better off making a properly-sized shield. The capacity of small shields is very heavily penalized.
5. 1. Not to mention that full ECM suite is good 450 tons of extra weight for your ship. Fire Control and Missile jammers can be very useful, but the Sensor one is a lot more dubious.
6. The railgun doesn't need such high capacitor recharge rate. 10cm railguns achieve their maximum rate of fire at Capacitor Recharge Rate 3, and you have 25. (The "Power" row in the description lists the power you need to fire the gun as first number, and the amount of power it's getting in 5 seconds as a second number. Excess power is wasted.)
7. Fire Control looks good, it just won't benefit much from electronic hardening. That only allows it to resist damage from microwaves, while driving the cost up by, i think, 2 times as much. Same applies to your MFCs and passive sensors.
7. 1. You will need an active sensor lock to target enemy ships, either from this ship or from an accompanying scout.
8. Missiles look pretty good to me, no issue here.
