[Opinions] Re: Nicknames for Octavia? (and a few others?)
Difficult. Octavia does not lend itself well to nicknames. Hmm.
I think my favorites from your general list would be Tavy and Vivi. I don't like the Oc-/Ot- nicknames at all, or any of the clocky ones either. Kit could work, I guess, but Cate really feels like a stretch (ditto Rudolf nn Bobby). If I met an Octavia nn Cate, I would guess that she was really an Octavia Catherine and that Cate was chosen in defiance of her fn instead of in relation to it. Davy from Octavia feels peculiar, so I would stick with Tavy, but if you're willing to consider Davy, perhaps I could interest you in Tavish? It would be more intuitive, and I like it more than many of your other choices. To be completely honest, I would stick with Adelaide and not worry about nicknames for Octavia. :-)
Minerva nn Mimi is as sweet as can be, but as far as Cordelia nn Caddy goes, I say no, no, no.