I found this "remove data file" change in Transmission to be a little confusing. The terminology isn't very user-friendly and it doesn't accurately reflect the action since it's actually removing all file*s* downloaded by the torrent, not one single file.
I saw you had closed a bug in your tracking system related to this, but I think you should give this further consideration. As long as the user doesn't touch the original torrent file, shouldn't Transmission be able to know where that original torrent file is (even if it no longer uses it to actually track the torrent) and be able to delete it via a "Remove all files" option? If somebody renames or moves this file themselves, that's their prerogative and then it doesn't matter if Transmission can't delete it. You said in the bug report for this that setting transmission to auto-delete the file is the solution, but it's rather backwards for me to have to re-save the torrent file if I want to open it in another client or email it to someone.
Regardless of whether you change the behavior or keep it exactly the same, I think you should still rename "Remove data file" to "Remove all files" (even if it doesn't remove the original .torrent like the original behavior did) or at the very least "Remove all data files" (though I personally think using the word "data" is rather cryptic and not very user-friendly).
remove data file does not remove the downloaded file so i am guessing it removes the .torrent tracker file. i'm looking for a way to remove everything related including tracker, download and list entry in transmission.