Unfortunately some lag is to be expected, especially with LiveTV in full HD. Your PC is doing a lot of work unlike normal tv. Future driver & software updates will hopefully improve things. Also make sure hardware acceleration is on (System>Video>Playback).
Sorry I can't offer any help with your tuner other than maybe rescanning your channels by location again. Did you try adding the MC001's own tuner in the web UI? Be curious to know the response time there.