No, dreams are a manifestation of YOUR subconscious and psyche, not someone else's. If anything, it would be more likely that you miss them or have some kind of unresolved feelings toward them. Or it could be a completely random occurrence. But you are not receiving brainwaves from someone else.
It's not about thinking about them or anything like that! You could have a dream about someone you have never met before, but seen in a crowd of people.. Your brain just makes images of people.. Randomly
No, having a dream about some one can mean so many different things but it always has to do with what you are feeling, what you have been thinking about, noticing subconsciously, or directly thinking about. What they are feeling or thinking can't be connected to you unless you noticed and started thinking about it yourself. If that makes any since to you.
No. Imagine how often someone dreams about famous people who probably don't even know the person and how many people must simultaneously dream about them. Also, has anyone ever told you that they had a dream about you but you didn't miss them?
Plus, there is no evidence that the human brain can (or does) do such a thing.