Does my SPOUSE count as a "YES" in the question: "Do you have children or financially support another person?" It seems that the question should state "Do not include significant other here!". So, do I put a "yes" or a "no" as I am married filing jointly?

Answer No.  A spouse is not a dependent.  You just file a Joint return.

If the other person is a spouse, you say No. They are referring to another person besides a spouse that you might support and could claim as a dependent on your tax return. A spouse can never be claimed as a dependent on a joint tax return.