rough idle and erratic shifting in low to mid-range speeds,are they related?

What is your question?

replaced spark plugs,TPS, and accelerator cable, but still not shifting as timely,or smoothly and idle, while improved quite a bit, is still getting "hung-up"(RPM stays high when braking then goes low in increments till full stop-sometimes the car will clunk, or wants to hop before final stop, then the RPM will settle @ approx. 500). One mechanic told me that the torque convertor is getting stuck!! Do I need to flush the tranny & change filter? or repairing the idle issue will solve the tranny issue? all this happens regardless of temp.,A/C being on, or other factors.