If you haven't got this figured out yet, one thing you mentioned was the accelerator pump may be a little loose. That will give you a stumble every time. It should be set to have 10 to 15 thousands play at wide open throttle and have tension at idle so it squirts whenever the throttle is moved the tiniest bit and should squirt strong all the way through the shot. For the fast idle there is only one thing that makes them idle fast and that is getting air or air fuel mix with the throttle down. A couple ways this could happen, one is a vacuum leak, another is secondary throttle plates open to far, or primary throttle plates open to far. You stated you set the secondary and fixed vacuum leaks so that leaves primary. It could be held open by the cruise control so make sure it is loose with the throttle closed or the fast idle on the choke is keeping it from closing all the way. If one of these is not the culprit then it may take a more hands on approach than can be done online.. If you have already figured it out then never mind..