I hear you re: Alice and Elon, Circles does solve that problem in a way that our money does not. But it does so in a way that lacks granularity... Suppose Elon is actually friendly in this situation and it takes a while for the locals to figure it out, all-or-nothing means that you essentially have one traitor, then two, then the pro-Elon faction and the anti-Elon faction, and then eventually everybody realizes that Elon is actually ok.
While this is occurring, anybody who is doing business with Elon is doing so at 1:1 rates, so nobody is being rewarded for taking the risk of getting to know him. And on the flip side of that, suppose we were wrong about him and he's actually a big problem for everybody around him... people have to either fully embrace his economic impact, or insulate against it all at once. It takes what could otherwise be a small mistake and forces you to make instead the big mistake. I think it's important to let people express their half-sure stance within the protocol rather than forcing them to put it all on the line.
As for the bidding war... imagine there's a mining company that has just showed up in town. Two grocery stores exist, one gives the miners a rate of 2:1 and the other gives them a rate of 3:1, because both stores don't trust them, but they have different tolerance for risk.
The 3:1 store has the opportunity to undercut the 2:1 store by switching to 1:1, and then the'll end up with all of the miner tokens. But then they have to spend that money somehow--probably by buying food from local farmers. Well if the mining operation ends up poisoning the aquifer and killing the crops, then the farmers are unlikely to accept that money, so it ends up only being useful for doing business with other miners, which isn't likely to be useful for the grocer because how much yttrium does a grocery store need anyhow.
Elsewhere in this thread somebody was arguing that I didn't need a new accounting system, I just need to talk to the people around me and only do business with the trustworthy ones. By encoding into prices the perceived risk that the other party might be a bad citizen in the future (thereby creating a liquidity problem for whoever holds their tokens) we create an incentive to actually have that conversation an act on what is learned from it. And that creates an incentive for that party to not be a bad citizen in the future.
Come to think of it, it might even enlist locals who have decided to take a risk on feeding the miners to take on a bit of a policing role. They now have a financial incentive to prevent the potential bad behavior. Circles has that dynamic too, but requiring somebody to be all in to even dabble makes it less likely to happen.