Wow, what an eclectic selection!
Here they are in my preference order:
Levi - cool, biblical and, since you love it, top!
Daniel - nice, classic, Dan's a great nn, inoffensive.
Austin - cool, unusual in a good way (like Levi)
Tristan - nice, bit posher and more twee than the others
Matthew - boring but nice enough
Manny - gosh, quite different. Good nn if he suits it but I'd want a 'proper' name, like Malachi (you seem to like biblical. I secretly love this name)
Zoe - such a lovely name
Hannah - lovely, bit too popular among the 30s-40s (parents of young DC) at the moment, so feels over-used.
Mary - nice, simple, classic. Maybe 'so ordinary (but actually barely used) its cool', like John is now.
Leah - ok, goes with your old testament theme. I always think leer, which isn't so nice.
Harper - celeb fashion name
Cadence - are you joking?