The question "how are things where you are" is similar to, but not quite the same as "how are you". The "how are you" question is generally asked when inquiring about someone personally. You are wanting to know how that person is doing as an individual. The question "how are things where you are" has a bit broader application and implies that you are wanting to know not just about how that person is as an individual but what is going on in their environment as well. In common usage the "how are you" question is often used in a very casual way as part of a polite greeting with the person asking it not always expecting a detailed response. Usually a simple "fine, how are you" in response is all that is expected. "How are things where you are" could open up the conversation to more detailed discussion of events in that person's life. I have used a similar phrase when chatting with friends that I have not seen for awhile and I want to catch up on what is going on in their lives.

Not quite. You could simply say "How are things?" Or "How are things with you?" but, "How are things where you are?" is asking about the location and not the person. Like maybe in the case of bad weather or political turmoil. When asking "How are you?", you are asking about the person.