Erm, that's supposing the religious person would actually want to suicide or do the ridiculous thing, rather than this itself being an expression of belief, affirmation, and argument of the religion. (I.e., as appeal to consequences, or saying negative things about the negation.)

The most reasonable interpretation I can find for your statement is that you're responding to this:

If a religious person says they'd do something ridiculous if God quit, we have a problem when implementing an FAI, since the FAI would either believe in Heaven or be inclined to help religious people do something ridiculous.

I agree, the goal would be to figure out what they would want if their beliefs were revised, and revising their circumstances so that God puts Himself out of the picture isn't quite the same as that.

The experiment also has other weaknesses:

• Ebay bidding shows that many people can't correctly answer hypothetical questions. Perhaps people will accidentally give false information when I ask.

• The question is obviously connected with a project related to athiesm. Perhaps some religious people will give false answers deliberately because they don't want projects related to athiesm to succeed.

• The relevant question is what the FAI thinks they would want if there were no God, not what they think they would want. A decent FAI would be able to do evolutionary psychology and many people can't, especially religious people who don't think evolution happened.

• It's not a real experiment. I'm not systematically finding these people, I'm just occasionally asking religious people what they think. There could easily be a selection effect since I'm not asking this question of random religious people.