3) First builds for the land-based warfactory for myself was annihlator, rocket, annihlator, and then rocket. Focus on the small island up north. You will need the ore to keep going.
4) Raptors are your friends. Save the ones you have. When you build the annihlators, the comp builds bombers. You need raptors to take them out.
Alright, have fun boys and girls. This last mission was a pain.
Just beat lvl 10 on hard. Got a few tips:
1) Move one of the warmachines to the coast (preferably the one on the right - in 2 turns can get to coast, 3 turns to the ore patch). You may need hunters to get rid of subs and control the sea. Try not to use hunters when they send fleets of bombers though because bombers kill them with one shot.
2) Use the stealth tanks you start with as screens. if you put them in a row or at a chock point while they are cloaked, enemy units will reveal them but won't attack them. They need a second ranged unit, which hopefully you kept the tanks out of the way from.
 "Necrophobia"){kind=icon}
 "Battalion: Ghosts"){kind=icon}