Tokyo-Kyoto trip Dec 27 to Jan 8

Hi everyone, my friends and I are going next week but we haven't quite finished planning yet. So far we have accommodations and a tentative plan of what we want to do.

Dec 27 to Jan 3: Tokyo
We're staying by the Keisei Koiwa station which I think is near Ueno. We're planning on taking the train around the city I think, so would it be easier to buy some kind of week pass or just purchase tickets as we need them? We'd also like to visit Fuji Q Highland one of these days, do you know which would be best? Their website says they're open every day so does it matter which one?

Jan 3 to 7: Kyoto
Since we have to take the shinkansen, should we purchase the JR pass ahead of time here is US? Or is it more practical to just buy individual tickets there. Since the JR pass is only good on JR lines, I don't know whether or not the week/2-week passes would be a waste of money or not.

Jan 7 to 8: Nagoya
We're departing from Nagoya so we figured we'd stay one night there.

This is a rough outline of our schedule, so I guess my main question is what should we do about transportation there? Is the weekly JR pass a good idea, and how easy is it to use other rail lines with or without it? Oh and how practical is it to purchase things with a credit card?

Thanks!

The shinkansen fare Tokyo - Kyoto - Nagoya is cheaper than a 7 day JR Pass. Within Tokyo various subways and private lines. Within Kyoto no JR transport. From Nagoya to CentralAir port no JR trains. So a JR Rail Pass makes no sense.

if you dont mind buying a ticket everytime you get on a train, buying single ticlets is cheaper than JR pass