Hi there,
Your itinerary sounds fantastic, but honestly I think to appreciate it you would need quite a bit more time. There is a lot there crammed into 8 days. Kyoto alone needs at least 4 days to see all the tourist spots. Also, it looks like most of your days are going to be filled with train travelling, so I hope you have taken that into account.
Having said that though, many people do what your planning and try to achieve as much as possible and still enjoy their trip, so if you don't mind quick looks through the different places then go for it! It isn't impossible.
If you do go ahead with it, I would recommend planning all the train travel, or at least get a rough idea on train times/timetables/distances etc. Here is a fantastic English link for train times in Japan...
http://www.hyperdia.com/cgi-english/hyperWeb.cgi Also, if you are planning on getting a JR pass, I would recommend not activating it until Day 3 because if you activate it on the 1st day, it will expire at 23.59.59 on Day 7. If you activate it on day 3 you will be able to use it to get back to Narita Airport and for the first two days, have you considered getting a SUICA & NEX pass?
Narita Express and Suica:
The Suica & NEX package for 3500 Yen consist of 1) a one way trip from Narita Airport to Tokyo (or Yokohama) by Narita Express and 2) a Suica card worth 2000 Yen (500 Yen refundable deposit plus 1500 Yen worth of train fares), a great deal, considering that the regular one way fare of the Narita Express alone is around 3000 Yen or more!
The Suica & NEX package can be purchased at Narita Airport only by travelers who hold a non-Japanese passport. There is a limit of one purchase per person. The suica can be used to pay the fare for virtually all trains in the Greater Tokyo region, including JR trains, subways and monorails, but excluding shinkansen. This would be ideal and cheaper to use in Tokyo than buying another JR pass.
Finally, in terms of accommodation, you could even consider some night trains to save on hotels and save time not wasting the days with train travel.
But like I said, it is possible, just a lot of planning to make the most of it needs to be involved! Hope that helps. Any more questions just ask.
Good luck!