I don't know your travel style - but it seems as though you like to move around a lot. One thing to consider is Golden Week if your visiting in Early May. Try and avoid major shinkansen trips on the major days like the plague!
https://www.japan-guide.com/e/e2282.htmlOne of the biggest problems first timers try and do is moving around so much with luggage. For example - why are you staying in Osaka and then moving in Kyoto. Just stay in one location as they are both really close to one another.
Most people tend to stay in Tokyo for 1 week and Kyoto/Osaka for 1 week. This allows you to branch out and take day trips a lot from these locations. For example - there would be easily over 2 weeks of day trips from Kyoto alone.
To give you an idea of the time needed to travel - here is a basic breakdown (this does not include going to your hotel!)
Osaka - Hiroshima: a bit under 2 hours (Shinkansen)
Hiroshima - Kyoto: a bit under 2 hours (Shinkansen)
Kyoto - Kanazawa: 2.5 - 3 hours
Kanazawa - Shirakawago - Takayama (buses)
Takayama - Matsumoto: 2.5 hours (local train = uncomfortable for long journey!)
Matsumoto - Kawaguchiko: 2.5 hours
Kawaguchiko - Tokyo: 2 hours
Feel free to ignore this - but I'd probably do the following:
7 nights: Stuff in Osaka/Kyoto
2 nights: Hiroshima / Miyajima
4 nights - Stuff in between Hiroshima - Tokyo (potentially 2 nights Takayama / 2 nights Kanazawa)
7 nights: Tokyo & Surrounds
The stuff mentioned above also would allow you to get away with a 7 day JR pass.
Doing Hiroshima/Miyajima in 1 day is technically possible - but it would not be much fun. I also agree that Day 11 is impossible. Kawaguchiko is nice and all - but it's a pain in the butt to get to and Matsumoto is mainly just a castle (although a nice castle). It a lot of traveling for so little pay-off at the current pace. Himeji or Hikone castles + towns would be a better pay off as a day trip from Kyoto.
When visiting Tokyo - you will find visiting particular areas will either float your boat or be a huge waste of time. For example - I think Ueno with it's nice park, museums and people watching make a great day. Some of the other locations you have mentioned you might visit and leave after 5 minutes (Roppongi etc).
Kamakura is also nice - but many people get templed out after Kyoto. Yokohama is nice - but I see Kamakura and Yokohama in the same day is too much. Slow down - spend more time in one place and see more stuff. As I always say - it's better spending time seeing stuff than traveling to see it!
When it comes to other suggestions on places to go - I don't know where to start.