If the US buddies up to Russia after the administration change, it's conceivable that the US gets its hands on Snowden in person.
Yeah, with Trump it's no-longer inconceivable that Ukraine is sold to Russia in exchange for Snowden. Unlikely, but hardly inconceivable.
The US isn't going to burn its bridges with its allies over this. It'll talk some smack, stomp its boots some, but it will be more bluster than anything.
Well, Trump is talking about NATO being of no importance to him. With Russia acting aggressively, you might understand why European nations aren't willing to risk trouble over a single individual.