Rooster,
I just got 22 MPG on a tank in the Forester, while I can double that in my Civic, which seems to require fewer repairs. The HX might not be an ideal vehicle but it hauls my ego adequately for now!
Someone on SubaruForester.org told me that the vacuum hose went to the cruise control unit and the grounding wire went to the bracket attaching the power steering lines to the intake manifold. I had not put the bracket back yet, so I had not been able to see where it went!
Every time that I opened my radiator cap after running it for at least fifteen minutes (with the heater on high (with the fan off, apparently)) I was able to add a couple ounces of coolant and burp out some air, but once I found the coolant temperature sensor, it was loose, and now my engine temperature reads properly. I do not have any idea why I kept finding air in my radiator. I do not have any leaks.
I am not worrying about it anymore.