The path to compromise that you describe exists, of course. But it's not the only way. For example, a zero-day in SGX combined with privileged access to AWS infrastructure could compromise Signal's SGX setup without any knowledge or collusion by Signal or Intel. As you note, it is not unreasonable for a project of Signal's stature to expect to face adversaries with such capabilities.
SGX does not cryptographically guarantee this. It cryptographically guarantees that the processor contains a legitimate provisioning key signed by Intel. Intel pinky promises that its processor will then only use this provisioning key in certain ways. This promise is essentially unauditable, and previous SGX bugs have shown that Intel isn't really in a position to make it anyway.
There are infinity dollars in the Federal Reserve. Pay-for requirements are a concern troll bludgeon used against only politically disfavored spending. Taxation (on the federal level) does not pay for services, but merely counteracts the inflationary effect of their provision in an indirect way. It's indirect enough that those who disregard it are not politically punished.
Much of the cost here comes from compliance with the ICANN gTLD program structure, not from running the underlying technical infrastructure (which is not limited to DNS - you also need EPP/RDAP/etc). See https://www.icann.org/en/registry-agreements for (hundred+ page) documents outlining registry responsibilities. Registries can outsource some of this to an ICANN-accredited "registry service provider", but should expect to pay upwards of hundreds of thousands of dollars yearly for the privilege.
How are you going to pay for the (substantial) cost of running a TLD without registration fee revenue? Is this a loss leader for other services? Are you operating on a 100% donation model?
> No parking, squatting, or reselling
How do you plan to tell the difference between a parked/squatted domain and one in legitimate use but offering no public-facing services?
It's CC-BY-SA/GFDL, and the underlying copyright belongs to the editors that wrote it. There is no commercial value in reselling access, and WMF does not have the right to relicense it.
Financially, they're not equivalent. If you buy your bread on credit, you get an interest-free loan, and benefit from the time value of the money that you otherwise would have paid immediately. As you correctly point out, this value comes from those fleeced by the arrangement. If my comment attributed any moral valence to the two options, that was unintentional.
If one is capable of managing one's finances (and paying the card off in full every month), credit cards are a useful tool. They're a problem if one can't manage one's finances.
Fiscally? Sure. In terms of liberty? Absolutely not. We are talking about public access to law, which is foundational to a free society.
Federal courts are not strictly limited by tax revenue in the same way that state courts are, and I am more sympathetic to this line of argument on the state level. Finding replacement revenue is a legitimate concern, but a secondary one due to the federal government's deficit spending privilege.