Easiest case in point: capital ships. Vastly overpowered to every other non capital in the game, but it's not their pure resource cost (except in small/early games) that makes them balanced, it's the 40 fleet supplies per ship (and to a smaller degree the need for research stations).
Nah, what makes capital ships a bit balanced (they aren't actually balanced though, a high lvl capital ship
is overpowered) is the need for crew research and it's high money cost.
I can easily churn out the first 4-6 capital ships in a short game on a small map, but after that it gets much harder to have more of them because of the research necessary for the crew. Ship points are no problem with most of the maps.
Missile Turret weak dammage protects Gauss cannons, and if guarded properly will give dammage to phase in ships, Hangars protect the entire system, but can be intercepted... notably hangars also have much more health.
Of course they would work together. Now add a flak turret and you have a nigh impregnable defense for early to middle game. (As long as the enemy doesn't come with multiple capital ships).
You just don't seem to Like it.
Nope. I have neither much sympathy or antipathy for the addition of new defense structures, as long as they're counter able, balanced and innovative.

I also wanted more in deep info of how those missile turrets should work. It's easy to say what they should do in theory but I'm more interested in the implementation of it into the game.

But imho the small gravity wells of Sins just don't lend themselves very well to much defenses. It's ok in other games like SupCom, because you have large, accessible maps and a diverse array of attack possibilities. But in Sins with the limited possibilities of moving inside a grav well you can make defenses overpowered very easily.
Just place a small fleet inside your defenses next time the enemy attacks, he'll stand no chance as long as he's no overpowering advantage already (nummeric and tech wise).
But this missile turret sounds more like something to make the need of a fleet added to your defenses needless. And that's what I don't like.