How do you make it clear that you aren't interested in anything but honest dating without being negative?

I think you're stressing about too much. Simply put if you like someone go with it and see where it leads. There are no rules sometimes. If it feels right then go with the flow. If issues come up deal with them at that moment. If you think ahead as to what he's going to be like, you may miss out on the natural beautiful order of falling in love. Communication is key. As you start to date someone you can more or less give your intentions but the truth is, our feelings change during relationships. Sometimes we want more and sometimes we want less.