it can be helpful to consider the thought as bad as the action for the purpose of weeding that behaviour out of our lives. Not that the thought is as bad as the action, because clearly it isn't.

Considering how many (ex)Christian folks struggle with guilt for having "impure thoughts", that appears to be a flawed approach. You can't control what kinds of thoughts spontaneously appear in your mind. Imo you should simply be aware that these thoughts are separate from your intentions and actions towards that person, and don't guide those actions.

Keep in mind that the Bible treats adultery as property crime against the father or husband of that particular woman. If you try to apply Jesus' teachings to infidelity specifically, you must wrestle with a bunch of historical and cultural baggage. Nothing wrong with treating a story as inspirational, but again, be aware that you're making Jesus more cool and progressive than he probably deserves.

Yeah, Jesus is prone to hyperbole, agree on that.