Is it (a US default) at all possible given all we know? and if yes, is it possible to envision what would happen specifically? If it will have global repercussions then maybe it is something the global community should insure against, somehow?
These are questions I'd like to have have a grip on. Not an economist, obviously.
Literally nobody knows the answer to these questions beyond the obvious answer of 'yes it's possible, and no it's not probable.' Everything beyond that is speculation, which is going to be more driven by ideological worldview than the unique specifics of the current situation.
People who think things won't change (not only referring to this specific issue) because the USD is still quite strong, remains the world reserve currency, and has survived rough waters in the past have a perfectly reasonable argument, even if it will inevitably be wrong one day. And those who take a bearish outlook on the situation also have a reasonable argument - we're obviously living through a major inflection point in history, the world has been de-dollarizing for decades, and the global economic (and geopolitical) winds are shifting. It's quite reasonable to see a storm on the horizon right now.
The hedging/insuring is "real" stuff. In an economic collapse any sort of financial vessel will become worthless. But after all is said and done, land, rare metals, and "things" in general will all maintain their value. Bill Gates and Ted Turner are currently the top 2 owners of farmland in the US. [1]
> Is it (a US default) at all possible given all we know?
An open question, nobody really knows. As I recall, the president has no option that isn't technically a constitutional violation. We might want to throw this to the SCOTUS and settle it.
These are questions I'd like to have have a grip on. Not an economist, obviously.