I wouldn't be so sure. The US government's powers often exceed the borders of the US.
Yes. That is true. The US government's powers extend to its vassal states, such as the UK and Germany.
You don't think it would be possible for the US government to force another country into revealing that sort of information? Remember Kim Dotcom? He was a German guy with German citizenship living in New Zealand. The FBI was even able to seize his hard drives too. And that's assuming that Satoshi isn't a US citizen living aboard. If he is, then both the IRS and the FBI would be after him.
With Germany and New Zealand, may be. What if Satoshi is actually living in Russia or Belarus? Or even in Venezuela or Bolivia? What the FBI is going to do if he is a resident of Russia?
Add the netherlands to that list
I know for a fact that the USA has a huge impact on some EU states, especially because of the huge financial power they have over them (think of import/export)
The top developer seems to know who he/she/it (Satoshi) is and claimed to have talked to it about btc 2.0.