You do not need a node, you can use public nodes. When you get to the point where you have a public app that has a lot of demand on a node, then you would consider running at least one node to support it.
I would highly recommend python, you can always move to JS later if you want. That's really the best options for Hive. There is a Rust library, but I don't know the state of it. Rarely would I recommend C/C++ for a project.
Thanks! Python certainly seems the most accessible. Didn't even think about just using the public at first though I knew that was possible.