Hitler was obsessed with eliminating every single Jew on the planet....certainly conquering the US and eliminating her Jews was going to be something Hitler would do, if he was in position to do so.
I don’t think so. There weren’t enough GERMANS to conquer the entire world. I think he was looking for room in Russia - that other miscalculation - where he thought France and UK would back off - indicates his real intentions.
But, even he did, we had a bit of time before he’d be able to stage an invasion of the US... Something about not having much of a navy outside the Ubootwaffe.