I got the Corsair H50 and the instructions said to use the rear fan as intake and my front fan is also intake. My top is exhaust.
So is it okay to have 2 intakes and 1 exhaust?
It's OK. The idea is to have the intake airflow volume be somewhat similar to the output. If the input is greater, then you have positive pressure which is good if you have intake dust filters. Also, you want the air flow to be smooth in one direction. In this case, from bottom to top.