I have a pair of geese, the gander is an american buff - considered to be one of the most docile geese breeds and the goose is a brecon buff. Raised and living with my runner ducks, the geese treat the ducks as their children. I have two coops of chickens and all the birds get free ranged together under supervision in the evening. My goose doesn't let the chickens get too close to her ducks, my gander only occasionally will stick that long neck of his out and make a move towards a chicken. The gander is a clown and full of mischief; I think he only does it for the fun of it. None of the chickens have ever been hurt by one of the geese. In fact, just last night one of my brahma pullets was running and screaming because she was being chased by a cockerel wanting to mate her. Not only did the head roo run over to chase the young upstart cockerel off, but my gander was the roo's back up.
All in all, I'd have to say they peacefully co-exist. I'm not sure the same would be true with a more aggressive breed of goose.