I did Chapter 2 and 5 all the way to the last mission then did it on insane all by myself. Only used 1 card the whole time, so here is my guide for everyone who is doing the missions on insane all by themselves.
Chapter 2 - Warfare on Torlan - In my opinion it was the hardest insane match I've ever played. What I did was grab the orb and capture the first prime node as fast as possible. Then grabbed the Leviathan and drove it to the Center Node and captured it. I defended the Center Node for about 3 minutes then I drove the Leviathan to the enemy prime node and shot the node with the leviathan until it was un-occupied then captured it. Your Leviathan will blow up when you capture the enemy prime, so wait about 2 minutes for the Leviathan to get back online, then drive to your prime node and take a right. It's a shortcut to the enemy core. Fit your leviathan into the enemys base and shoot the core, you should be able to pull off about 7-10 damage before they all gun you down. (If you can't fit your leviathan in the enemies base, make a run for the enemy core and shoot it with your flak cannon, (it does 4 damage a shot) As you have the lead, (Red Core: 100 - Blue Core: 90) go back to your Leviathan at your base and defend the central mode for about 15 minutes until it reaches overtime and you win. (Whoever has the biggest lead at the end get's the least amount of points taken away at overtime)
Chapter 3 - Team Deathmatch on Gateway - Use one of your cards that decreases the enemies teammates by two, making it 2v2. I followed my teammate until he reached the space area, then I grabbed the shield belt and health vials until the enemies entered. Then I destroyed them with the Flak Cannon, (which is in the snowy area in a building, grab the thigh pads while you're at it) and grabbed more health vials and shield belt. Let your teammate grab a shield belt when you already get one. Once your full on armor, follow your teammate around to get his back. I never finished the match I waited 20 minutes until the match ended.
Chapter 4 - Team Deathmatch on Deimos - The easiest mission in my opinion. Once you start the match enter the portal which sends you to another building with a plasma cannon thing in it. Pick off enemies until the vehicle blows up. The vehicle is very accurate and it kills enemies in 1-2 shots max.
Chapter 5 - Defeat Akasha 1v1 - I did this on my first try. All you have to do is camp the area where the Bio Gun is and hold down LT until the secondary fire is fully charged, and grab the Armored Vest. When you see her try to hit her with the secondary fire, it has a little bit of auto aim so it should be fairly easy to hit her with it. It usually kills her in one shot, since she rarely has any armor on. If you get hit and you dont have any armor left, grab the three 25 health packs which are right in front of the Bio Gun. Do this for 20 minutes and whoever has the highest score at the end wins the match. It was pretty easy since I did it my first try with no help from anyone at all.