Out of the two sensors on the throttle body, I always look at the TPS as the problem creator first, but before spending any cash getting a bunch of new sensors, I'd take the throttle body off and give all the cavities a good cleaning - the air passage associated with the idle motor can sometimes get clogged causing idling problems.
Hi-idle and miss fire can be caused by a number of things, including vacuum leaks. I normally disconnect all extraneous vacuum lines, plug the holes or hoses, and then give it a try - the only two that you really need to test the motor are the lines to the fuel pressure regulator and the MAP sensor, all the rest you can temporarily do without for this test. Another area of potential vacuum leak is around the manifold, but before you start to take anything apart, I'd recommend performing a vacuum test - here's
a good writeup on vacuum testing basics.
Another good test to perform is the running fuel pressure test & fuel pressure regulator test - poor pressure can cause it to run bad.