1) is not possible for now so I agree fully with your idea.
2) 100% POSSIBLE...(I have 4 different spawning abilities used at elast 500 times each in battle )
3) By nature...turrets (if were talking static defense) are tracking..but if your talkiing actually seeing the weapons turn to face target..then not yet and once again I fully agree with you.
4) ALL SHIPS CAN MOVE!! Ask kiedjor..just adding that ability to ever single ship makes the game so much more fluid!