"Frankly, I think belief in the supernatural should be screenable in an employment application": screening prospective employees on the basis of their religious beliefs is illegal in many places. For example, in the US see http://www.eeoc.gov/laws/types/religion.cfm and in Australia see https://www.fairwork.gov.au/how-we-will-help/templates-and-g...

I think there are good reasons for these laws. If it is legal to discriminate in employment against religious minorities, that can contribute to their disconnection from broader society, which could promote radicalisation and similar problems. You also have to consider that there are many countries where religious discrimination is official government policy - how easy is it for an open atheist to get a job in Saudi Arabia? - and for Western countries to prohibit religious discrimination is a good way of sending a message about it at the global level (whether or not anyone in places like Saudi Arabia are listening.)