Sidda - I'm not a fan of this, it just looks and sounds awkward to me, sorry.
Jubilee - I quite like this name, and I don't think it'd be that awkward unless you're quite close.
Naomi - This is nice, and although it's not one I'd use myself I can imagine it'd be cute on someone else's baby.
Eleanor - I love Eleanor, I've recently fallen in love with it myself. I think that Eleanor Jubilee would be cute, or Eleanor Scout/Eleanor Grey.
Scout - I like Scout, although for me it's a bit of a guilty pleasure. I do think it's lovely as a nickname for Scarlett too.
Grey - I prefer this on boys, but it's lovely as a middle name.
Whittaker, nn Whit - Very handsome. I love the nn Whit, although I do think I prefer Whittaker with only one 't'.
Forester, nn Four - I like Forester, but the nickname Four isn't that intuitive for me, at least not in my accent, and it's not really my style.
Kaiser, nn Kai - Kaiser is okay, but for me it's a bit like calling your child King. I love the nickname Kai though.
Saevar [prn Sy-var] - I kind of like this one, but initially I'd pronounce it say-var so the spelling could be confusing. I think it'd be a wonderful middle name though.
Darby - Handsome. Very nice.