Government debt isn't debt in the way that most people think. It would be more correct to think of it as the savings held by non-government. The neo-classical belief is that the government is creating fiscal space when they sell securities, enabling them to create more money to spend into the economy, but the money they received for the securities didn't come from the FIRE sector and not the real economy (ergo, they didn't create fiscal space in the real economy).

Most countries that I've looked at don't include government securities (which are effectively savings) in their monetary aggregates. The one exception I've found is Japan, who include it in broadly defined money (L).

I'm glad to hear you say that you'd only use a CD or UBI after implementing a tax on economic rents. That clears a lot up, actually.