Maybe I didn't understand you properly, but wouldn't it be better to make a list of acceptable licenses, instead of a single license?
Those are minor details. And I would dare guessing that for most of the users it would make pretty much zero difference which free license (FSF approved) the choose for their projects. P.S.: by making source world-readable I was referring to unix permissions, which would of course only have an effect for people with toolserver accounts.