Ok, I wanted to be sure it wasn't my fault that the pump was cavitating. I moved my inline thermometer to the output side. This solved about 90 percent of the problems I had last week brewing. The other 10 percent may be attributed to bumping things, crappy priming, stepping on hoses, or whatever clutsy thing I did today. I didn't check pump housing or magnet for freeplay yet. After I brewed I did a little test while circulating some PBW through everything. I had the pump running wide open and had awesome flow at 8 feet off the ground in my bathroom. That's plenty high for me.
So, I just want to say that the pump isn't as bad as I previously thought. The USA Pump guys are very quick to respond to any e-mails and e-bay questions. They're quite willing to help you out. Very impressive. I'll let you know if there is any other issues.