Chickens are a weird mixture of pets and livestock. They are used for food but they can be pets.
However, even though they can be pets, no one needs more than a few roosters for their flock at the most and it's downright unethical and irresponsible to rehome an aggressive roo unless the person you're giving him to plans on eating him. Culling an aggressive bird is the most responsible thing to do. As for older hens it depends on one's needs and management style. I think both approaches are fine as long as the birds are treated humanely