I agree with all your assessments.
I saw the movie with my husband (who did not like it) but I did.
I'll admit I covered my face during the bugs sequence (couldn't handle it) but the rest of the movie was glorious.
I found myself paying the most attention during the scenes with Naomi and King Kong. They were beautifully filmed, directed and acted. She is some radiant actress.
I also enjoyed Adrien's performance. I am a fan of his anyway but he brought a great deal of sensitivity to the part.
Jack Black I had a little trouble with. Robert Armstrong, to me, in the first film nailed the part but I felt in some scenes Jack Black was good and in others he was not.
The supporting characters provided good and interesting acting, the young sailor and his mentor, the experienced sea captain and Lumpy, the cook. Gotta love Andy Serkis. Is there anything he can't do?
As mentioned, the special effects were phenomenal but you expect that of a Peter Jackson film. However, the acting is what sold me on the picture.
One disappointment, however, was the music - some parts of it were great - other parts of the movie I could barely hear it. Perhaps I am spoiled by the excellent soundtrack of all the LOTR movies.
Anyway, I will go see it again and I give Peter Jackson credit for tackling such a project.
I also agree that Black is a little odd for his part. He overacts a bit. Still, I like him in general, I don't mind minor flaws (if it is a flaw-- his character, after all, is a self-promoter), and variety adds spice. Jackson is certainly aware of Black's circus-barker style and by casting him, deliberately intended his performance style to be a part of the film. Someone like Cruise or Pitt in that role would possibly sink the film IMHO...