Wait... but I have three intake on the bottom, three intake on the side, three exhaust in the top (rad) and one exhaust in the back (140MM all others 120MM) Does that mean I'm good?
If you can do FTB or BTT then positive pressure CAN work for you. Positive pressure is a designed path with pressure pushing the air out. But you NEED a path. A fully vented case will be inefficient.
The main thing about positive pressure, as far as I know, is the dust problem. Positive pressure tends to keep dust and crap out of the cracks and ports. To an extent.