Stoning the Adulterer is Effective Because?

[Simsim]

As with any religion, it leaves enough lack for bad people to feel justified. Moderate religious people may want to do no harm, but they are the fertile soil where the fundies thrive.

Agree with you
Unfortunately the popular religious moderation is still, basically, deduced from scriptures and religious teachings. this makes this moderation unstable and let it have many gates to extremism. This is why, as you say, moderate religiosity is a fertile soil for fundies. Because moderation is, mainly, a fundamentalism with some vague amendments.

To establish a real religious moderation you should put the authority of religion under the authority of human values and human rights. And it needs to put also the authority of religious texts under the authority of reason. This, for theists, does not mean to deny religion or religious texts but to put the in the right place. I have many Muslim friends who are this kind of theists. Lovely and rational really but, unluckily, still minority.