Hi,
Yes, all the places I mentioned are covered under the Kansai Area Pass. Please see the map in the link I gave above. If you wanted to go beyond that, there is also the Kansai Area Wide Pass which is considerably more expensive, but you can take the bullet train (including the fastest one, the Nozomi) and get from Osaka to Okayama in as little as 45 minutes (and it's 180km away).
Okayama is famous for its castle, plus Korakuen Garden, one of Japan's Top 3, and also the Handayama Garden. If you'd like to get off the beaten trail for a while, the half day hike up to Konpirasan in Kotohira is stunning. Going to Takamatsu is also nice - it has one of Japan's finest gardens also, called Ritsurin.
You can get a tiny discount for buying it online. There is one advantage though - if you buy it in Japan, you can only do it one time only. So if you buy it online, and want to buy another in Japan, you can use 2 passes in Japan (as long as the times don't overlap).
Osaka is best at night, to see Dotonbori, plus the night views from the Umeda Sky Bldg, and Abeno Harukas Bldg are wonderful. Kobe has some good places as well, including its Nankinmachi Chinatown, Arima hot spring, Sorakuen Garden, ropeway, and mountaintop view from Mt. Rokko.
Best of luck.