Rough idle coupled with acceleration issues

I've had some issues with this car. Back in May I had the intake manifold gasket, the waterpump, and the thermostat replaced after the coolant in my radiator corroded just about everything. I got that taken care of then noticed my car was still idling wierdly (when I started the car while it was still warm it would rev then decrease to almost stalling out). The wierd idling is a little more mellow these days, but I've started seeing a new symptom as of very recently: I can take my foot off the gas and my car will still slowly, but surely accelerate of its own accord. I have to ride my break and when its like that, it revs at around 1500rpms. This is terrifying! I was told replacing the fuel pump would help that and that the O2 sensor would fix the idling, I'm about to go get those done, but I have a gut feeling there is more to this. Can someone please tell me if the o2 and fuel filter would save my baby or is there more work that I should have done?