Is it possible to see total listening time in the current month in Pandora One

No, Pandora does not go out of its way to not play that song. The explanation is simpler - Pandora can play only songs for which it has distribution rights. For some songs it does not have the rights (usually because of the pricing for the particular song), so while it will create a radio station with similar music, it might never get to play that particular song.

If you click on the options link for the station in question then click on station details and it will list station seeds, thumbed-up songs and thumbed-down songs for that station. All the way to the right of each thumbed-up song there is an X. If you click on the X it will remove that thumbs-up.