I wouldn't call One Piece a "strikingly conservative anime". I mean, the anarchy and fighting the corrupt government, ha all the gender bending sexuality stuff, adult humor in general, and well in general all the writing Oda provided from the manga. There are more wild ones out there sure, but I wouldn't call it conservative.
As for the anime stagnating on the pace and structure of Oda's original story, as you say. Well, it has identical pace to the manga. Ideally we'd like it if it could adapt 2 chapters an episode and have a brisk pace, but they're both releasing the same quantity of story each week (more or less), and how fast you go through the manga chapter is up to you. As for structure, I don't see any change there.
Anyways, I'll agree lack of blood is an issue. I don't get why they do it, having blood actually makes violence seem less safe and cool than sanitizing it. It's better for everyone, including kids, to see the fights with blood versus without blood for One Piece, in my humble opinion.