First 17 days in Japan – Tokyo->Osaka->Hakone->Tokyo

Hey all! I'll be going to Japan with my partner very soon for our honey moon! This is both of our first times in Japan and wanted to be certain that this plan is realistic and that I am not missing any key details about executing it and I have a few questions! Thanks for your time.

Plan

Yama no Chaya is locked in. The hotels are booked too but changing the dates a bit may be possible if there's something exceptional we want to make happen. teamLabs Borderless has also been bought already. We will be taking public transport the entire way and hoping to make it as comfortable and stress-free as possible for us both! I'm imagining we will both have one backpack and one luggage each, or maybe just share one larger luggage together if that sounds more optimal, or maybe buying a luggage while we are out there? I'm imagining for each day we will likely do one or two things and keep the rest of the day kinda loose and open-ended for roaming and emergent activities so we aren't chasing down activities hour-by-hour. We will be going to either Day 1 or Day 2 of Kawagoe Matsuri, unless you think both days are worth it! Anything with a question mark is something I'm not to sure about and I'm open to input or even replacing.

Here's a summary from my big excel spread-sheet!

Questions

1. We really want to see the Open Air Museum over in Hakone. Are our Hakone plans too tight for this when you consider travel from Osaka early in the morning, getting up to the Museum, and getting back to the ryokan(Yama No CHaya) by around 3-5pm? Especially if we possibly have luggage on us to worry about?
2. Not all of our hotels seem to do luggage delivery services. Is carrying our luggage or using a 7/11/Family-Mart/etc something we should do? And if so, how early should we be sending our luggage over? This luggage stuff is probably something I'm the most worried about and I'm willing to spare no expense to make handling this part as easy as possible. Maybe I've been influenced by TikTok comments and such but I have this feeling that dragging a luggage on a bus or train is an "annoying tourist" thing to do. Especially in Hakone since I hear the busses there are small.
3. I can't seem to find a way to buy tickets for the Tezuka Museum ahead of time. Is it assumed that we must buy it in-person day-of?
4. I don't feel like I'm taking advantage of Osaka/Kyoto much. Due to scheduling, we only have 3 solid days there outside of days mostly spent traveling. I feel ignorant on this matter, but I get the vibe that Osaka's main attraction is primarily Drinking and Food and once you've done that there isn't much else to do as a tourist besides maybe Universal Studios and the Aquarium which is difficult to want to give a whole day to out of the 3 days we are there. Maybe I managed to miss all the other media about things to do in Osaka but I am open to recommendations for other experiences to share there or possibly in Kyoto if day-trips aren't much of an issue.
5. We will be using Ubigi on our Pixel(Android) phones for our eSIM, has anyone had experience with them?
6. Is there anything else that I should be trying to secure ahead of time?
7. Open to any other recommendations as well!

General Notes

As far as recommendations go, we don't really care too much for night-life stuff with booze and bars and such, but we're both huge nerds with interests in books/manga/anime that is maybe more on the "older" side(Di Gi Charat, Tezuka stuff, Beserk, Ghost in the Shell, Cowboy Bebop, FLCL, etc) and some newer stuff(Land of the Lustrous, Beastars, Delicious in Dungeon, etc) and huge into tech and gaming(console/pc gaming, retro gaming, programming, diy electronics, pc-building, Pokémon, Final Fantasy(14), etc) and general art and music events are also interesting to us. Def looking for more experiences to share together!

We tried to do the new Nintendo Museum but unfortunately did not make the random lottery. Open to trying to reserve other things if there's a chance for it!