I re-read Ran a month or so ago, and came to the conclusion that while it was quite good so wasn't it as good as I felt the first time. I believe that the initial surprising charm of the work made a strong impression upon me, which didn't remain to the same degree when I already knew what to expect; still a really good manga though, but I believe it could have been even more if it was more elaborated. As you said, could definitely have done more with the brother. May I ask what exactly was divisive about it?
Yes, it's about ballet. Nothing groundbreaking, just a good, enjoyable manga with good characters and story progression. Pretty much a sports manga.
Ok about Narutaru. Don't know if I may have overstated it; it isn't the most disturbing or even close to what I have encountered in manga, but it has two things that might be a bit unpleasant. For example, Bokurano by the same author and the anime Now and Then, Here and There was both far more disturbing for me, if you have seen or read either. Also Ef - Tales of Melodies was worse. And, while I'm on the topic, so has, though not in any way disturbing, 5 Centimeters per second emotionally scarred me more than anything else - great movie though.
I did start Atelier earlier, but never got into it. Will probably restart it on your recommendation.