Where do these fit into the saga scenario? Are they both played after the 3rd scenario of the Dark Riders, or do they fit in between some of the Dark Rider scenarios?

The order I think would be: Shadow of the Past, The Old Forest, Fog in the Barrow-downs, A Knife in the Dark, Flight to the Ford.

If you read the books you would know but joking aside the above post is correct, the events of the old forest and sequentially the barrow downs are in between the first and second quest in the black riders box.

On that note- would you have the Ring Bearer along for the ride in "The Old Forest"? I reckon you would!

Indeed you would

Dang, should've brought Frodo to Gencon!