Shizuoka and surrounding April 2020

Hi
We (both in their 60) are planning a trip to Shizuoka and surroundings in 1st week of Apr 20. Flight in Nagoya and out Tokyo. My plan are below.

1 - Arr Nagoya morning. Bus ride to Hamamatsu (3 nights)
Sightseeing Hamamatsu Fruit Park, Ryotanji Temple, Kanzanji Spa, sand dunes, castle etc.
Sightseeing Kakegawa Castle, Kakegawa flower n Bird park, Rengeji-lke Park, Yaizu Fish Market etc

2 - Hamamatsu to Samatakyo Onsen (1 night)
short hike and the suspension bridge

3 - Samatakyo Onsen to Shizuoka (2 nights)
Sightseeing Nihondaira Plateau, Mknozan Toshogu shrine, Sumpa Park etc
Sightseeing Shimizu Port, Miho no Matsubara

4 - Shizuoka to Izu Peninsula (2 nights in Toi and 2 nights in Ito - Total 4 nights)
Sightseeing round the Peninsula area. Is this doable?

5 - Izu Peninsula - Tokyo (1 night)
6 - Home

I would like to know is the frequency of the local transportation (buses) good? I only intend to rent a car from Shizuoka to Izu Peninsula and return the car in Atami.
Where can i find the schedule of the local buses in Hamamatsu, Kakegawa, Shizuoka, Shimizu and in Samatakyo.
Any day pass I can pick up or any places that I can give a miss or add. Please advise.

Best Regards.