well, all things considered, it hasn't been that bad. Turns out where my cold in PVC meets the shower mixer, there's a leak.
and, since the PVC is all glued in, I'll have to cut it out and replace the whole cold side. Of course, due to the fact that I couldn't check for a leak until it was all together, this was the only way to find out. and, it's not too bad a leak, but anything is unacceptable.
hardware store run tomorrow.