Re: WDYT of these name's I'd consider naming my (hypothetical) daughter?
I'd prefer Ashe as a nn for Ashley; combustion products just don't appeal to me.
Constance is fine.
Dorothea is very nice; I was at school with a Dorothea who never had a nn, so it can be done!
Juno and Minerva are absolutely not to my taste at all.
Liliana is very ornate; I prefer Lilian, but not enough to use.
Maribelle is also frilly. Maribel is calmer and quieter.
Rowan is strictly masculine; Rowena is pleasant.
Yumi is not easy to say. I checked on this site; please do the same. Apart from that, the meanings are confusing, though that wouldn't matter because on a non-Japanese person it will inevitably be thought to sound like Yummy, which is unfortunate.