Photographic Assignment

My latest assignment has got me really working/thinking. I am going to shoot up to 100 youth volunteers (possibly more, but doubtful) as a group for a newspaper ad. It was my idea. I mentioned it last year, when, for the first time, we featured six select volunteers in an ad. Prior to last year, we used stock images. I said it would be fun to include as many as would show up. I think perhaps I thought that after another year went by, I would finally know what I'm doing. :) Here's the photo from last year:

They are a very nice looking group, so that made my  job easier! Looking at this photo almost a year later, I still think it's a nice image although I would pose them differently if I had it to do again. 

Here's what I need to consider while planning a shot of this nature:

1. Lighting and shadowing (if I'm lucky, it'll be slightly overcast, better yet, partly cloudy!)

2. Lighting angle (where will the sun be at that time of day)

3. Location (background elements, etc.)

4. To include architectural elements, or not (?!?) My thinking is that with a large group photo, trying to incorporate anything else into the image will be too much. I think the focus should be on the kids, not the building. But, then again, because it is such a large group shot, each person won't be seen very well any way, so maybe I should incorporate architecture. (hmm ... I am too wishy washy to be a photographer when I grow up)

5. Is it possible (feasible) to shoot in more than one location with this large of a group?

6. If I shoot into the sun with their backs to the sun, will the shadow casting on each other be an issue? 

7. What if it rains? 

8. I'd like to do something a little more creative than the standard "shoot from above" shot, but considering my inexperience, I'm not sure if I should. I guess if time allows, I could try it after doing the safe shots.

9. What else?