Visiting Japan May 2019

Hi, my husband and I are visiting Japan between the 14th and the 24th of May 2019.

Our itinerary is the following:
14/05 - arrive at Osaka Airport - go to hotel (hotel in Osaka from the 14th to the 17th)
15 and 16 /05 - visit Osaka and near by temples/castles/parks
17/05 - travel Osaka to Nara (spend the day in Nara) - travel to Kyoto (in the evening - hotel in Kyoto from the 17th to the 20th)
18 and 19 /05 - visit Kyoto
20 /05 - travel from Kyoto to Hakone (to see mount Fuji) and at the end of the day travel to Tokyo (Hotel at Tokyo from the 20th to the 24th)
21, 22, 23 /05 - visit Tokyo, and in one of the days go to disneyland
24/05 - depart from Tokyo airport

From what we saw in your fare calculator, the JP RailPass is more expensive that what we would spend in single trips.
Can you confirm this is true?
Also, if we don't buy the JPRailpass, should we buy single tickets, or regional? Can we buy them online and reserve seats?
Is this itinerary feasible?

thanks in advance!
Looking forward to our trip!