JR Pass in February 2024 to vist different cities

Hello, community, the next month we will be in Japan for 18 days for the first time and I would like to ask a couple of questions with you.

We have the JR Pass of 14 days to do this:

• Tokio -> Nikko (roundtrip)
• Tokio -> Yokohama (roundtrip
• Tokio -> Hakone Gora
• Hakone Gora -> Nagoya -> Takayama
• Takayama -> Kanazawa
• Kanazawa -> Kyoto
• Kyoto -> Nara (roundtrip)
• Kyoto -> Hiroshima + Miyajima

• Hiroshima -> Osaka

• Any recommendation for the previous routes using the JR Pass?

• Is using the JR Pass instead of individual tickets worth it? (I also like the flexibility of using only the pass instead of purchase individually)
• Should I reserve seats on any of those routes?
• I bought it at the new price, do I have access to the Nazomi trains?
• Where can I find the discounts on activities having JR Pass?

Thanks in advance.