Does an open ear represent an open heart?

Not necessarily. Just because someone is listening to you, doesn't mean they really have their heart in it. With a lot of people, it could just mean that they're really good communicators who can not only listen, but understand what's being said. And like you said, some people really are just curious and want to get in your business without really caring about you personally. Watch out for that. That's why you can't open up to just anyone.