The US moved its focus away from Europe and the Middle East to the Pacific region. The US forms the POTA (Pacific Ocean Treaty Alliance) together with Japan, Okhotsk (Russian Far East), South Korea, the Philippines, Thailand, Malaysia, Indonesia, Australia, New Zealand, Chile, Argentina, Peru, Colombia, Mexico and Canada (I might've forgot some). Therefore, the US is still a superpower, but just doesn't focus much on Europe and the Middle East anymore. It does, however, maintain the NATO with Europe, but it's become a much more lose organization.
As for what happens inside the US, I can't really say much as I'm not an expert in American politics, but I think the US is a little les free than it is now, and there is some instability here and there, particularly in the Southwest, where some states have considered breaking the union.
The EFU as a whole is not included in the Centrosphere, nor in the American Sphere. Inside the EFU, only Germany, Austria and Slovenia are part of the Centrosphere, while only France and the Netherlands can be included in the American Sphere. The American Sphere mainly includes the POTA, some other American and Asian countries, and the UK, while the North, the Netherlands and France can be included.