Fred, I've always found that developing a shot list is always much more simple after developing a storyboard or writing a script (even if I'm not specifically going to USE that script for my "reality show" ;-)
A major challenge in developing a storyboard or script is visualization - even though many of us are adequate-to-fantastic behind the lens, we may be lacking in ability to "SEE" things in our minds before we shoot. I suppose that's why there are scriptwriters who cannot shoot, storyboard artists who cannot write script, shooters who cannot visualize :-)
But, if YOU can SEE in your mind's eye what you want/need to cover. If your research has given you elements and aspects of the church's ongoing history that you want to focus upon. If you've decided to take a chronological approach or are going to do time shifting, or flashbacks from current to past, you'll need to be aware of the history, the contents, and the folks who can help you CARRY your story in that direction, or along that path.
Having a production outline based on the information of written history and documentation of the church's growth over the years, old photos, etc. will help you generate a storyboard of sorts. And NO you do not have to be an artist to develop this (stick figures work fine) will be a tremendous asset to you in figuring out exactly the shots you want for your shot sheet.
On the other hand, if you're gifted at seeing things in your head and want to pursue development of a shot sheet from that resource there's nothing in the books that says you cannot accomplish your goal - development of a production outline that will give you some concept of how to approach your final production and shoot/edit for it.
Just determine where you want to start with your church's story, and where you want to take it, and how you want to get there. You may find that doing the other stuff first ISN'T necessary for your project, but I still think it would help give you a clearer understanding of the comments, shots, angles and archival photo use you will need to do the best possible video production reflecting both your vision and the subject's story.
I can't wait until you're able to share the final outcome of your documentary with us all.