Kind of doubtful. They can't really control individual DNS servers within top level domains. What they could do is what you mention, throttle or cut off access for an entire TLD like .mil or .gov And others that I won't even mention on this forum.
There's another threat you have left off which is flooding the internet with useless TLDs. They would be able to intentionally dilute the namespace and remove the influence of say "ford.com" and replace it with "ford.sucks". Even though "freerepublic.com" would not be affected there would be more imposter sites. The crucial factor for that kind of attack would be the involvement of big search engines like google. Together with foreign controlled ICANN they would be able to balkanize and break up the internet.
They've essentially already done that. The TLD system is nothing but a license to print almost unlimited amounts of money. Companies have to protect their trademarks in dozens of domains that they have zero interest in using. It's a huge waste of money for many businesses.
I find your detailed information intersting.
But ICANN charges a fee for every website. That means they register every domain name and it’s IP address as well as I understand it.
In other words, yes ICANN can delete specific websites unless there’s something I’m missing.