Busy Days with JR Kanto Pass?

Basically, I'm trying to shave the cost of this trip down as much as possible, and I think I've checked all my bases, but I feel like I'm missing something. Maybe there's a better pass for me than the JR Kanto pass? (I can't get regular JR, as I'll be in Japan for more than 90 days.) Also, in addition to just double checking to make sure all these routes are covered under Kanto (unless I've noted otherwise), if you do happen to see anything that just seems downright stupid (like "why are you staying THERE? That's so far away!"), please do let me know.

I appreciate the help! My brain is tired from planning, and I knew I'd need another set of eyes.

Here's the itinerary:

Day 1): Arrive at Narita international airport and grab me a JR Kanto pass. Narita Express > Nippori > Shinjuku (Yamanote) > Otsuki (Chuo) > Kawaguchiko on Fujikyu > Kawaguchiko Station Inn. Sleep there overnight to prepare for Fuji the next day. Hopefully the Kanto pass will have mostly paid for itself just in this trip.

Day 2): Climb Fuji. We'd leave for the first bus, which I guess costs 2100 yen round trip. Then we'd climb and come back down and stay at the hotel again. (Is climbing Fuji in one day and seeing the temple on top a bad idea if we make sure to stay hydrated and take some breaks, especially around stations 7 and 8? I've heard both sides.)

Day 3): To get to our hotel would require Kawaguchiko to Otsuki on Fujikyu > Shinjuku (Chuo) > Nippori (Yamanote) > Minamisenju (Joban). Then we'd spend the rest of the day doing random popular whatnots like Shibuya crossing, Sunshine City, etc.

Thus ends the Kanto Pass, right? (Is there another pass you'd suggest getting here, or is it not worth it?)

Day 4): Ghibli Museum in Mitaka (Minamisenju to Ueno > Kanda (on Keihin Tohoku Line) > Kichijoji or Mitaka (on Chuo Line), then whatever random stuff in Tokyo we still want to do. Probably just shopping and walking around.

Day 5): Here's the kicker, and I don't know how to make this one cheaper. Minamisenju > Shinjuku > Osaki > Shinagawa > Nagoya > Maibara. Or whatever route will get us from Tokyo to Maibara, as I need to end up in Hikone. This route is so expensive, even without shinkansen.

Any tips? Any passes I'm missing? Suggestions?

Thanks so much!