As far as the idle problem goes I would test your (IAC) Idle air control valve and (TPS) throttle position sensor. Start there and you might find that's the reason for the miss as well. If you don't know what they look like google each one and look at google images it shows a lot of different pics. Hope this helps. The only other thing I can think of is whoever built your motor has the timing off a tooth either crank to cam or on the distributor but it would prob run a lot worse if that was the case