One more item to note -- if at all possible we do not like to do FF inside the church. Our preference is to always encourage the B&G to do these outdoors in natural light. However, there are situations where the B&G really want them inside the church. Or sometimes it's raining and there isn't another option.
No flash is always easier in terms of minimal setup, but if you can work in some supplemental lighting, then it can go a long way in making the FF shots look nice. Just make sure you have all your ducks in a row.

