I took the car in for a second opinion. No offense meant to Chris, just if I was going to spend $13,000 on the car I wanted to have someone else take a look. Everyone in the PCA to whom I mentioned the issue said "you are going to take it to Steinel's right?". So for my second opinion I took it over to Steinel's. Eric was very nice, he took me for a test drive in the car - asking me about various issues. His initial impression was that I did not have a broken headstud. I was a bit leery of this, but asked him to go ahead and complete the testing.
As a side note, it seems like every time something goes on with the car I am out of town. For the purchase I was in San Diego, for this round of testing I was in Washington DC.
I called Eric on Thursday to get the verdict. He had opened / removed the valve covers and tested all of the head studs. They all seemed to be in good shape, all taking torque and so on. The oil leak was coming from a bit higher in the engine. He was able to correct that issue, along with the high idle and a broken rocker. The transmission was out of adjustment, so he (they) were able to correct the second shifting issue. He also adjusted the clutch and the throttle. The clutch was very grabby - it seemed it was not releasing completely. Correcting the problem was an adjustment. The throttle was only giving me ~60% of the full travel. Adjusting it should give more gas and quicker acceleration. He also noted that the car has a LSD - which is a nice surprise. He recommended new brake pads and rotors, so I had him do that. I thought for a minute about doing it myself - I like doing brakes and need to get a wrench on the car at some point - but this was quicker. There are some DE's in early June I'd like to attend. He also thought that refilling the AC might correct the problems with that. We'll try it and see.
I'm looking forward to getting the car back on Wednesday. I wish I had allowed Chris to do the testing in early May - he would have found similar results I am sure and the car would have been back sooner. Oh well - I was so freaked out about the possible $13K in expenses that I lost sight of that as a worst case scenario.
Total cost is not yet determined, but while expensive it should not be anywhere near $13K. The purchase was not as bad as I thought.