This thread indirectly helped me out a lot. I found that the facebook app and business calendar pro app were both really keeping the phone awake. I have removed both and am relying on google calendar (built into phone) and the facebook page via browser instead now.
I was hoping to find a fix for wifi in MIUI, but have so far been unsuccessful. It keeps the phone awake no matter what I do (awake meaning not in deep sleep, but clocked at 245 mhz instead).