You cannot record "on demand" programmes on the SA8300HD because they are not the same signal as a regular channel, therefore they are unrecordable. It's not because they are "flagged".
I see no reason that you shouldn't be able to record anything on your DVD Recorder that comes out the S-video port. The only programmes that MAY be "flagged" are PPV at this time. This is not really "copying", this is "recording while watching".