I would suggest taking it as it comes rather than planning much. For a trip like you are planning I'd think it would make more sense to just take an easier pace and mess around for a few hours in the places where you want to smell the roses rather than take days off. I'd think a few hours in Ohiopyle would be plenty unless you decide to go rafting. There really isn't all that much to see in town, at least that was my impression after have been there hundreds of times in my canoeing and kayaking days.

That said do what ever strikes you as the most fun and have a great trip.