Kate - not keen as a standalone, full name. Too short and plain for my personal taste, I think.
Caitlin - quite like it. I don't have any class based associations on it at all.
Mary-Kate- pretty sound but I really would just think Olsen.
Lana- like it. I suppose some kids might pick up on the anal thing, I don't know. Doubt it, tbh.
Bryony- really like it and think it's very underused nowadays. Yes, it's the feminine of Brian but so what? Lots of names have m/f variants
Andi- like it but agree it's not great as a full name. Andrina? Anya-Diane?!?
Holly- like it. Don't think it needs a nn
Emma- it's ok. I think I'm with your DH on finding it a bit plain.
How about:
Kathryn, Katie, Catrin, Karina, Catriona, Katerina,
Mary-Jane, Mary-Anne, Mary-Louise, Mia-Kate, Mala-Kate, Mila-Kate, Megan-Kate, Martha-Kate, Maisie-Kate,
Lara, Lena, Lila, Lyla, Lyra, Laura, Lorna, Lauren, Leanna, Leandra
Bianca, Bridget, Bronwen, Bethan,
Anya, Anais, Anna, Annie, Anika, Abbie, Ally, Ashley, Amelie, Ayla, Aria, April, Ariel, Agnes, Astrid, Aphra, Alice
Hazel, Heidi, Hattie, Hetty, Honey, Honor, Hebe, Halle, Hayley
Emily, Emery, Emmeline, Emmie, Ella, Eva, Elsa, Erica, Esther, Eliza