Wow, yeah you've been putting in work. Good work too, but you still need to see some Hara ;-) I like the thoughts on Death by Hanging and I've actually noticed that some people are disappointed in Oshima in general after seeing it.
Dude you need to see LOTS of Mizoguchi, later Ozu, Naruse, Suzuki, Kobayashi, Yoshida, and the best Oshima's - everything pre Realm of the Senses.
Japan has the highest number of great films out of any country in the world, there's never been a low period. Keep going!
I second those recommendations. Plus you need to get into Kazuo Hara!
You should add these two films to your list. I don't think Japanese films, or any films for that matter, get any better.
“When a Woman Ascends the Stairs” (1960) directed by Mikio Naruse
“Harakiri” (1962) directed by Masaki Kobayashi