Do Asgardian gods count as non-US?
But yeah, as a Brit I totally agree. I think Captain Britain would be REALLY hard to do right without some serious tweaking to his origin, but characters like Black Knight and especially Union Jack would work better. Hell, Union Jack could show up on the SHIELD TV series as an agent of MI:13 from Britain, as a guest or supporting character.
But I love Taskmaster and would rather see him on the big screen, hopefully with a costume more like his UDON one. I like his classic-current costume, but its really silly and the UDON one is just badass cool!