Tough questions. I was trying to finish up my own book over the winter break and thought about doing the same. I even posted a part of the beginning on Steemit to see if people would have interest in it. So far, not so much, but I'l probably going to still post at least three chapters when the whole thing is done.
If you were paid for the drafts, you should check that you didn't sign over any distribution rights, or gave anyone exclusivity to them or derivatives of them. I didn't have the same issue, since my book is self published, never marketed, badly proofread and it makes sense that Volume 1 has sold about 12 copies since 2015.
In that aspect, serialization works. I can't see how I could have had it all so close to being done if I didn't shove half of it out the door and said "THERE, you're done. I'm not going to obsessively change you constantly, hunting for perfection and ending up with nothing".
Serialization is how I even got to actually building Volume 1 as it was, started a version of the book by posting chapters of it on a forum. They've since been remade to not be as awful, but having people ask what happens next was a good motivator go keep going and keep actually finish it... some day.
As for posting it as its own thing or on your account, I'd personally go for having it be its own thing. It something I should have done for Tale of Doom, and I probably will when I decide to post more of it. Or it would be nice if Steemit allowed something like subaccounts, or if there was something on the blockchain dedicated to books, like we've got Steepshot for pictures.
Paid on steemit. They were never published anywhere else. Scroll down my profile for like a year and see.
SOON.
In any case, looks like I'll be creating a seperate account for the project.