I found a major gaffe in the file_type clause. The fix was simple (after making glade2 again because xd-unstable put GTK only glade in its place). Searching for music file_type is very fast, and it clearly shows the clumsiness of GNOME's mime-type handling--lots of text files in the results. I added a popup menu to select open file or open parent from the results list. Opening Nautilus views is dodgy on my system, but I let it pass because I see the same problem in other apps.
My last set of changes made the indexer very stable, I don't see any tmp files left next to the db indicating the indexer failed. I'm going to take the time to handle the .progress files when the indexer fails and close that bug. Two other changes I want to make soon are rename the vfs-module and fix the URI format. That will put me in a good position to start replacing Medusa's backend.