[An automatic searching enemy - aiming - shooting turret]

Why so much logic, though?  My similar build was a back of rotating lasers with one detector that was set to enemy.  One button rotated the turret clockwise; the detector output rotated it counter.  (This doesn't ALWAYS seem to work - you can add a NOT gate to rotate it clockwise if the detector output is NOT present.

 

That's a good  solution ,I had tried this and which done pretty good

[An automatic searching enemy - aiming - shooting turret]

Nope,I only made it fire itself,the driving job should be done by player. :-\

[An automatic searching enemy - aiming - shooting turret]

Gif

[An automatic searching enemy - aiming - shooting turret]

I used a lot of logic gates to make this turret ;D.

But unfortunately, it was 360 degrees and used too much of the parts, which made it not well used on bigger warships. :-\