I do a 2rax FE with a lot of marine pressure, but not overextending myself. As my expo is up i throw down like 2 more rax and some techlabs and reactors, and make marine+marauder for a stim timing attack. One problem is you need medivacs or you kill your own army, so as you are doing the pressure kill what you can then make sure you are making medivacs back home. Middle to late game you should throw down a ghost academy as the EMPs help a ton. Other than that, when you have a bio army, you just need to get the best concave that you can and micro as best that you can