Thanks to everyone in advance; the forum has been of great help!

I'm traveling to Japan in October. It's my second time there, but it is my husband's first, so we're going to some of the more "typical" places (Tokyo, Kyoto, Osaka), but we have a couple of days to go to lesser know places. I've been thinking about Kanazawa, but it may be too similar to Kyoto. Would you still recommend it? Or are there other places (maybe Takayama) that would add more dimension and originality to our trip?

Currently, my itinerary looks like this:
Day 1 to 5: Tokyo

Day 6: Tokyo to Kanazawa

Day 7: Kanazawa

Day 8: Kanazawa to Kyoto

Day 9: Kyoto

Day 10: Kyoto

Day 11: Kyoto to Osaka

Day 12: Osaka

Day 13: Osaka to Hakone

Day 14: Hakone

Day 15: Hakone to Tokyo

Additionally, I liked the idea of ending in Hakone to get a nice ryokan with some private bath to relax towards the end of the trip, but do you think it's better to go instead to an onsen town for a night and use that other night to add to Kanazawa (or whichever other place you recommend). At one point, I also thought about Naoshima, but it seemed like it was too much of a journey for a place that only needed about a day to visit.

So big question marks are Kanazawa and Hakone and whether they're the best use of my time considering the other places we will visit.

(ps I have visited Nikko and Nara in the past and would prefer not to repeat)

That works.
You could visit Unazuki Onsen on the way to Kanazawa or stop at an onsen town just south on the way to Kyoto
The Takayama fall festival is Oct 9 & 10.
What is your plan for Osaka?

Thank you so much! So would you do Kanazawa instead of Takayama?

As for my plans in Osaka, I'm mostly interested in the street food and getting to know the city (haven't been in the past), but still planning on details. I'm open to suggestions if you have any!

I would choose Takayama over Kanazawa,.
I prefer the setting and the feel of Takayama.

Kanazawa is a small city. Given how short your visit is, Kanazawa depends on how much of a draw Kenrokuen is to you. I've visited that city at least four times, most recently in November, 2019. That was my only visit since they opened the Hokuriku shinkansen line and there was a lot of foreign tourists.

Takayama is a town. It is flat and easy to walk or bike. I would go there via Toyama and leave for Kyoto via Nagoya (some of the runs of the limited express train go from Takayama all the way to Kyoto). You would want to take the bus up to Hida no Sato. There is a shrine walk east of tpwn. Takayama Jinya is interesting. The street with the old-sytle buildings. Hida beef. Ramen. Am sure there are more tourists there now than the last time I was there which was at least 15 years ago, maybe 20.

Ok, Osaka. You do want to go to Osakajo-koen and visit the castle. Read the history of the castle. You need to try Osaka-style okonomiyaki.

Is Day 15 the day you leave Japan? That question suggests that you don't necessarily need to spend the night before your flight. Which airport and what is your departure time?

What I meant to write was:
.... you don't necessarily need to spend the night before your flight in Tokyo.