Japan travel route

Hi,

From 1st of April 2024 to night of 21st our planned itinerary is as follows:

1- Tokyo – Narita
2- Tokyo (01.04-05.04)
3- Osaka (05.04-08.04)
4- Kyoto (08.04-11.04)
5- Kumano (11.04-13.04)
6- Fukuoka (13.04-15.04)
7- Kumamoto (15.04-16.04)
8- Beppu (16.04-17.04)
9- Shirakawa Village (17.04-19.04)
10- Hakone (19.04-21.04)
11- Tokyo – Narita

Is it possible to follow this route especially when large distance between central Japan and Kyushu is considered? (without using Nozomi and Mizuho)

Is it possible to reserve trains to be used in advance in Tokyo?

Thank you for your answer :)