Your instinct is correct. When we address people (or things!) we use names. We don't have a vocative case in English - or any real cases for that matter - but if we did have a vocative case, this would be it. Just as you might make a name out of 'dog' and say 'Hello, dog' to a dog you see in the park, you'd say "Goodbye chair. Hello couch" to your furniture. It's fine. Don't spend too much time talking to inanimate objects, though. It probably isn't healthy. :)

No you don't need to use the definite article. However, you are probably not going to get a response.

I think you don't need to use the article

Drake, yeah, I know. It's a hypothetical situation. :) Don't worry, I don't talk to my furniture. :)

You don't even have to talk.