Bobby 4/8/2010You have a few problems going on, check the fuses for the cruise and cluster if you haven't yet. if you have then you'll need to do some electric troubleshooting, but theres a good chance the cluster is the problem.
the shifting issues would worry me I would have a pro trani guy drive it. It jerking when slowing down could be a motor or trani mount does it also jerk when first putting it in gear?
Bobby 4/9/2010Knowing these cars a little i know they can start to slip a bit, being this one is getting pretty old. I don't think you're looking at anything that will be a quick easy fix. I imagine its been driven prettyy hard through the years, Check the motor and transission mounts see if any of them need to be replaced.
Thats a pretty detailed engine with a lot of vacuum and electronics to make it run at peak performance.
As for your speedo, odom and cruise, I don't think they are related, check your fuses see if they possible blew out.
Cruise control check the actuator and the switch, it runs off vacuum so check vacuum lines for leaks.