I am with you on most of the ideas. A Chiiusa / Sailor Quartet centered story, I am all for that, or at least for a good chunk of an arc, like Gohan at the beginning of the Buu saga. If that happens, I want the Quartet to have some sort of special relationship or what have you with Hotaru aka Sailor Saturn, for all intese she saved their lives. If it wasn't for her, they wouldn't be alive.
A Codename Sailor V adaption, some of the side story getting an adaption.
Can't go wrong with any of these.