Many airlines in the U.K especially EasyJet/RyanAir have a shortage of pilots. EasyJet has even lowered their experience required. This means more int. pilots. The problem with U.S pilots is that, U.S licenses are different than European licenses and it's a pain to have to convert them because it takes time and work. Plus you have to have the right to work in the U.K, that takes time to get. Still, very possible. The reason why Cathay,Emirates,Singapore,etc have a lot of int pilots is because they use a different license system similar to the U.S, plus you don't have to be a citizen of the respective country to work at the airlines.
As far as the first question, the ones that I know of are:
China Airlines(1/4 of pilots are foreign)