>Rigorous examinations for English fluency and for competency in their alleged field of expertise would be a good start.

I have a good friend who came in as H1B and is now a citizen. I have also worked with many H1Bs who were absolutely terrible and definitely shouldn't be in the country. What I've noticed is that the key difference seems to be which country you are from. He is from a first world country with education standards. The ones who were no good came from the third world where fake diplomas are for sale cheap. It won't matter what qualifications we screen for if the third world happily prints up those fake qualifications for a small fee. I was sent so many candidates to interview who knew absolutely nothing, but they shamelessly put the proper keywords on their resume.