Using names in written dialogue to keep track of who's saying what doesn't strike me as unlikely at all - I'm fairly sure it's true! It's so frustrating to read a long spiel of dialogue and have no idea who's speaking, and thus what's really going on... Using names more than in actual speech seems like a good solution. After all, written dialogue hardly ever accurately records the patterns of real speech, given how much we all um and er and never finish sentences.

Similarly, I think I might use people's names when speaking to them when the conversation is being conducted in a largeish group, particularly when it's quite lively and everyone's speaking across each other a bit. Again, it just makes it clearer whose ideas you're referring to.

I think you're right about the names/exasperation correlation, but that isn't the only one.