I don't really dislike
Bethany as far as just the sound of it goes. I just think of it as a somewhat manufactured name in that it's a place name in the Bible, not a personal name, and has only started to be used as such recently. That just makes it seem like a fad name to me, like
Madison. It's a name that will go out of style. I have a name like that myself. Mine was an invented name, it came into style, and then it went out of style. I know that when these names go out of style, people then tend to say that they don't like them. And that kind of hurts your feelings. So I wouldn't want to give my daughter a name like that. I hope that made sense. I prefer old, classic names.
Susannah and
Clara are both nice. It's true that
Susannah has the (to me) disadvantage of the nicknames
Sue and
Suzy, which I dislike. And even if you didn't want her called by those, I think people would still tend to do it. If those nicknames don't bother you, I'd pick
Susannah. It's really beautiful. If they do bother you, I'd pick
Clara. It's a fine old name that I think is ready for revival.