It's really okay to talk about any topic on hubski, but remember that hate and disrespect will be follow up with people ignoring you. If you like a topic, feel free to start a conversation about it.
Frankly, I feel this is all that hubski needs as an intro, its up to a user to get what they want out of the site. Each user interacts with other users and if you post things you find interesting, people you find interesting should follow you and vice versa. If you are not interested in anything then don't expect anyone else to be interested in you.