After doing some more research, I think that maybe doing only 2-3 days of Kyoto/Osake might be enough to get an impression of the area.

Instead of spending more time checking out smaller villages, maybe we should go to Okinawa or South Korea instead?
I prefer seeing many different places in a short period of time over visiting fewer places more thoroughly (during my first trip to NYC, I got bored after two days and felt like I had seen it all - which obviously wasn't true, but that's how it felt to me).

What do you think? Is Okinawa worth visiting? Or maybe Busan?
Would that be an alternative? Or is that a stupid idea?