SuperSync has a trash function for permanently deleting files. Select files to "trash" and right click on them to reveal the "Put in Trash" or use the Action menu.
You may delete tracks that are on files on your local machine. SuperSync does not support deleting files over the internet.
To view the file path of the files you are deleting, use the "Get Info" on the track.
You may remove files from the trash by selecting the files and choosing "Remove from Trash".
Once you are certain that the files marked for deleting should be permanently deleted, select "Empty Trash" from the control menu. Files will then be added to the delete queue for iTunes and server updates. (You may need to uncheck the iTunes updater from File> Pause iTunes Updates if you have previously paused those updates.)