I agree that some kind of cleanup function would be useful. Alternatively to having it as an option, i.e., clean ups would always be performed automatically, there could be a cleanup button (like the connect or pause button). If you press it, all completed tasks are removed.
Another question concerns what exactly should be cleaned up. I can think of:
- removing rootnodes of completed downloads
- removing entries in the par2 window of completed repairs/unrars
- removing remaining content of download folder after successful unrar
- removing empty folders after successful unrar
Maybe the choice of what to clean up could be adjusted in the options menu. Not everybody likes to do have the same tasks performed automatically.
To make the cleanup function/option perfect, it would also allow moving some or all files remaining in the download folder after a successful unrar. For instance, often there are NFO files or Jpegs associated with a download, but they are not included in the rar archives. Some would like to keep them, some don't.