Hi there,
Visiting Kansai (the area where Osaka, Kyoto, Nara and Kobe) is located is great! There is a lot to see and visit. Actually there is so much that it is hard to recommend something without knowing your interests. As general highlights, I would recommend a visit to Kyomizudera, Kinkakuji and Nishiki market in Kyoto, in Osaka be sure to go shopping in Namba and visit the Shinsekai area, for a good nostalgic impression.
Also if you are interested in Japanese culture, history and tradition. Consider a visit to Nara. Let me know what your general interests are and I can give you more ideas.
As for the JR Pass. It may sounds strange but I think that it would be better to buy normal tickets as you travel. A 7 day JR Pass is great when you use it for a return Tokyo - Kyoto or Tokyo - Osaka. Nagoya however is not too far from Osaka and you simply don't have enough travel costs for a JR Pass to pay of.
Hope this helps!
Daniel