Hi there,
Since you posted your detailed itinerary here, I've rolled it all in one answer for better reference.
I would certainly recommend a 7 Day JR Pass for your travel. This because a return ticket Tokyo - Osaka is about the same price as a 7 Day JR Pass, basically if you use the pass for the return any additional travel is FREE! For instance you can use the JR Pass for travel to Disneyland, Universtal Studio or the return trip to Narita Airport.
As you may already know, the Nozomi train is not covered but you can use the Hikari Super Express instead for travel to Osaka. The trains are the same but the only difference is that the Hikari makes a couple more stops on the way to Osaka. When using Hyperdia be sure to deselect the search option NOZOMI / MIZUHO / HAYABUSA (SHINKANSEN), this way you can find the right trains.
I hope this helps!
Daniel