Thanks for lengthy review/sharing
It was really interesting to read, especially since your perspective is so different to mine, and we relate to/are frustrated with Yozo in completely different places 
(but I also hate how he treats women)
Yes, but the main problem is, these are short stories, so it’s hard to recommend one specific “book”, because I don’t think they were released in fixed collections.
If you want to see how “a strong woman character” looks in Dazai’s version, then I recommend either ヴィヨンの妻 (short story) or 斜陽 (novel). The problem I had with 斜陽, though, is that it’s very slow paced - and it’s supposed to be, because it’s a book about post-war slump, but for me it was a bit hard to read.
ヴィヨンの妻 is shorter, so the action is faster, too.
And I don’t necessarily agree with women’s choices in the above works. 
(only short stories below)
My personal favs are 畜犬談, 服装に就いて and 駈込み訴え.
The first two are still ranting about life problems, but the topics are much less grandiose (cynophobia and clothes, respectively) and the overall mood is lighter, too. Problems are still described in an emotional, over-the-top way, but here it results in more comedic effect.
駈込み訴え I think I mentioned before either in ABC or 人間失格 home thread - it’s written from Judas’ POV, about why he betrayed Jesus, and Judas sounds here like a grumpy boyfriend being angry at his partner.
More classic/typical Dazai which I liked would be 富嶽百景 (it describes Dazai’s stay at Misaka Pass and how his second marriage was arranged). 2nd place would go to another ~景, 東京八景.
As in the titles, the first is about Dazai’s thoughts related to Fuji, and the second about his Tokyo memories.
眉山 is an interesting one, because it ends on an empathetic note where Dazai and his drinking companions actually feel a little guilty about not being nice enough to someone.
And there is 女生徒 where the narrator is a teenager girl. It’s written in a stream of consciousness mode.
If you decide to read any of the above (or any Dazai at all), be sure to let me know 
And I hope I didn’t mess up while checking the Japanese titles