In your xml file you may want to just remove this line. <runtime></runtime> It will not show 0, just nothing shows on screen. If you remove or comment out the section of code that controls this, it applies to all shows.
Only because you may have other video in your xml file that you want to insert the length.
Update on the stars if using 4.1 SDK videoplayer. To keep the stars away for good after watching a show and the Resume button shows with stars here is the code that includes 2 statements to remove stars:
screen.ClearButtons()
if regread(show.contentid) <> invalid and regread(show.contentid).toint() >=30 then
screen.AddButton(1, "Resume Playing")
screen.AddButton(2, "Play from Beginning")
screen.SetStaticRatingEnabled(false)
else
screen.addbutton(2,"Play")
screen.SetStaticRatingEnabled(false)
end if
screen.SetContent(show)
screen.Show()