Just one small thing about Turo: is metalbending even possible as a first bending experience? I guess he might do it on accident somehow (might have happened in one of the comics I think?) then not know how to replicate it again until much later (though that raises the question of why no one before Toph did so). Normally people have to learn seismic sensing to see the little bits of Earth, then they bend the metal.
Well, to be fair, I think metal banding might have just been a case of no one trying it since it requires a really deep attunment with the earth. So maybe Turo is just that close to the earth that he just kind of... felt how to do it?