Unless you disabled maintenance, I think space stations still require it. Also, is this design a support sensor station ? That's a very high sensor range for something armed only for point defense and short range engagements. If you're planning on mass producing them, probably better to make a dedicated sensor platform and the rest with the minimum backup to do their jobs if the other one is destroyed.
If it stays at a planet, it'll be kept up by the maintenance facilities there. You only have breakage once you leave base. Still, one or two engineering facilities might not be a bad call, since they're cheap/small and they reduce the risk if your planet ever runs out of base capacity. (And, as mentioned above, they'll give you MSP to replace lasers that break in combat).
Those lasers are too big for PD. You're only shooting once every 15 seconds which could be a problem with multiple salvos.
I don't think it's a size thing. Power 6-2 means they're 10cm lasers, but without any cap recharge rate tech. OP should invest in a couple levels of that (in Power & Propulsion), get recharge rate 3, and re-create the laser and turret designs. He even has enough power to keep them firing every 5 seconds, too.