*Terran side notes* Top Diamond Terran here, Playing as Terran you need to take advantage of Medivacs and the ability to drop in multiple areas at once, I feel this works best against Zerg (Their third isn't usually guarded that well). Stick to Bio most the time because of the mobilty. Take advantaged of the power of widow mines, they are a very powerful unit in the bio mix with proper micro. Just make sure you don't fall behind in bases, and if you fell yourself having to much money, just throw down another CC. No matter how far behind you are, as long as you have 3-3 Marines, you're still in the game.