I personally found nothing wrong with the AI one tip that works for me is stopping the unit before it gets to the building then they Auto attack the other buildings and about the IP missiles not maneuvering around planets wich I believe RedGoldandGreen mentioned if you put a Lvl 3 IP on the side of your planet you can hit a target on the other side of the planet or just use a planet destroyer to remove the afor mentioned planet BTW 20 orbital devastators=Epic Ownage against anything