Forum Moderators: not2easy
Which of the above need model releases? Also should their be a specific copyright clause on the websites relating to copying photos from the website? I'm assuming these are not "crowd shots"
Should you or they seek permission? Well, that's not really a legal scenario but one of negotiation! Having said that, as a third or external party I would not want nor expect to be burdened with such responsibilities.
Usual disclaimer applies - This is merely my understanding and I could be completely mistaken. I am not qualified to give anything resembling legal advice. Seek it from someone who is...
Syzygy
When photographing for a customer, I'd recommend to get model releases for every identifiable person on the photo -or- to make clear to the customer prior to the job that it's THEIR responsibility to obtain the model releases, and that they are not entitled to use the photos unless they obtain the respective model releases. As you are on location during the photoshoot, working with the people, it definitely makes sense to have the models sign the release, unless there is a dedicated person from the customer on location as well. Then I'd have THEM do the legal stuff.
BTW, all of the scenarios you describe would require a model release if you intend to use the images. At least if you want to be on the safe side. The last scenario (church leader publishes to social networking sites) is certainly gray area, but again, I'd recommend to always stay on the safe side.