Craig - you are right about language bias. We have a mental acuity component in a hiring assessment we use and we always have to be mindful of the fact that if English is your second language, you won't score as high. Of course, that doesn't mean you're not as smart - in fact, we tend to round up a point or two (it's a stanine system with 9 being the highest).
For example, the question "a cup is to a saucer is like a bowl is to a " dish. If English isn't your primary language, the word saucer might trip you up.
I also agree about IQ not being everything. However, we absolute discard candidates that can't meet a minimum on the mental acuity scale. Does that mean once in a blue moon we miss hiring a good candidate? Sure, it could mean that. However, we know from experience it filters out dozens that we shouldn't hire in the process...