Hi Again!
Arriving at Kansai Airport is known to be a problem as trains stop riding after midnight. I would recommend staying the first night at a Hotel near to Kansai Airport and traveling on the next morning. There are multiple budget hotels in the area starting around 4,000yen/night. Alternatively you could take a Taxi to Osaka but they are very expansive and could cost over 20,000yen.
I think your plans for Kyoto and Osaka look great! I'd add a visit to Kyomizudera temple if you have to time as it is one of the most beautiful temples in Kyoto.
For travel to Kawaguchiko, take the Shinkansen from Kyoto - Mishima station. From here you can use an express but to Kawaguchiko. The route is pretty long and instead I would recommend going to Tokyo instead and make a day trip to Kawaguchiko later on from Tokyo.
As for where to stay in Osaka, look for accommodations around Namba, Shinsai Bashi, Minami. This is the best area to stay in. As for Kyoto try to stay in the city center near Kawaramachi / Shichijou / Goin.
Hope this helps!
Daniel