My dad's got an S35, although he's been using my OPPO 971H for a couple years now. Yes, the optical and analog stereo audio outputs will both be active at once, as will the component and s-video outputs. The one possible problem I see is the optical - one of the devices you're connecting to will need to accept an optical digital input. I don't know about LeapFrogs, but there are a lot of TV's out there that lack an optical input.