Finch sounds too crimped for a first name. I don't know if that makes sense, but I don't know how else to put it, so for me it is more GP material. If I were to pick I think I would say it feels more boyish to me, because of the similarity to
Finn, though birds of similar type tend to seem more girlish to me generally.
Prue is more nicknamey imo.
Niko is cool, but it feels like it's trying to be.
Remy is awesome. I think it has a softness, but it still very masculine.
Pollux is handsome, but also sounds like an illness and I don't know how I feel about the two of those things in conjunction.
Keaton is just too last namey for me.
Clement feels slimy (Clem=Phlegm), but I love the meaning.