Garnet and Sapphie are dead.
Specifically they died when the castle crashed on earth.- Jossed. Garnet appears in episode 7 and Sapphie in episode 16.
Airi will be the first JP human protagonist to not have a romantic interest.
'Nuff said. Laura is the one in charge of the romantic sub-plot for this season.- Sort of confirmed since we don't see anyone express an interest in her in the show, but she apparently got married to an unseen person in the future.
Luea will never get a human form.
Her would-be transformations are constantly getting foiled by other pets. It'll become a Running Gag and she'll be this season's Marie.- Jossed. She gets it in episode 23.
Airi's daughter from the epilogue...
... is the messiah and will probably save Jewel Land from some great future catastrophe. Note that we don't see or hear mention of whatever man might be living with Airi, so she was probably a virgin birth to boot.