Geese like to free range and really do not need a coop other than to get in out of the weather..
I give mine a lean to that is open to the south.... They like to sleep outside with the mini horses..
Are you planning on locking yours up at night?
A coop should have windows on 2 sides at least for cross ventilation and light.
Yes they will be locked up we live in the country and we have a very bad mountain lion, bob cat, racoon, and possum problem. Also would my ducks be ok with me geese? I really want to have the geese a closed in run for when im not home and let them free range the rest of the time.