The external player used for "Open in Player" context menu should be configurable.  Or if it is, I couldn't find it in the configuration.

The "normal" player used for other media files (as configured in the window manager) isn't necessarily a good choice for playing (and controlling) individual audio tracks easily.  This should be a configurable option.  It can still default to the "normal" player, but it should be allowed to be changed if needed.