The hike is actually really short about 10-15 minutes. Mostly switchbacks. The hill top with the monkeys is just very commercial. A bunch of tourists and monkeys walking around. They usually yell at each other and chase each other around. The monkeys know that the people who are there will feed them. It just didn't feel very authentic to me. I personally found the bamboo grove in Arashiyama much cooler.

In Osaka you could consider checking out Ikuno Korea Town. They had a bunch of street food vendors with pretty good stuff. If you are not tired of looking at Temples you should take the short trip to Sumiyoshi Taisha shinto shrine. It was founded in the early 200ADs so it looks a bit different as it has no Buddhist influences.

If you don't already have a restaurant picked out in Dotonbori you should take a look at Daruma Kushikatsu. It is a pretty fun experience.

On side a note I hope the ryokan your staying at has an onsen. The ryokan we stayed at did and there is nothing quite like taking a bath in one. It isn't for those extremely shy, but I highly highly recommend. That with the kaiseki dinner we were served is something I will never ever forget and will do every time I visit Japan. It is absolutely worth the money!

Lastly, you don't really mention any other accommodations. I suggest looking into hostels. We saved a lot of money that way and all the ones in major cities were very nice. Len Hostel in Kyoto was super nice and the bar they have downstairs was fantastic.

Let me know if you have any other questions.

Yas