I finally got my high idle condition under control. Turns out it's super easy to get the throttle body position sensor out of wack. I cleaned the TB before I painted it so once I reinstalled it, the computer though it needed to be in the old, dirty position so it was getting way more air than it needed. It took several cycle of running it then letting it sit then running it to get it to relearn the new position.
My tach still isn't working and I'm not reading any rpm on the ODB2 reader either. I did get a P0335 code about the crankshaft position sensor when I took it out for a drive so I'm going to start digging into that and see if that's the problem.