The bottom of the tv guide currently shows the title and the description. There is not really any room for a another line, so should I be showing the sub title (if we have it) in place of the title?
Since the title is already seen up top, I think that would be a great idea. You're not really loosing anything, and you would be able to show both the title and sub-title.
If later on, sub-title is placed in the popup, would it also show in Recordings?