Ok so you're working with a bank 1 lean code and a missfire code. I would rule out the MAF due to the fact that it's not affecting all cylinders. If I were you I would take it somewhere and get a scantool thrown on it and look at your fuel trims. +/- 10% is about as much fluctuation as you want, I would also look at the IAC mainly because it seems like a cold start issue.