Are MIT or BSD licenses any better in this regard? I mean, I'm sure the american boilerplate written by american lawyers would hold up in an american court - but if I'm not under the American legal system, how do I know I don't need different boilerplate?

For all I know the MIT license might be (say) invalid in France, because it's written in the wrong language, or invalid in Russia because the the first paragraph isn't written in ALL CAPS, or invalid in Taiwan because it doesn't expressly waive moral rights to the integrity of the work.