Backyard Chickens

I live in a suburb and have a large back yard. I would like to have two Buff Orpington hens for the yard (for eggs and their bug-eating ability).

I have no experience with this.

If I kept them in a hen-house at night and let them out during the daytime, would they tend to make a lot of noise? (Thinking of the neighbors).

Or fly away? I have heard that Buff Orpingtons get fat and heavy and might not hop the fence with a nice, grassy yard of their own.

Or am I dreaming a fool's dream? LOL. Thanks for any information provided.