As far as the original question, the reason you don't want to raise them with the other chicks is because they're grow faster and eat a lot more than a non-meat type, and can crowd out, trample or starve out the smaller chicks.
If you want to keep them strictly as pets, they'd still need to be kept apart from the other chicks as they'd need a restricted diet and encouraged to exercise, to keep their weight as light as possible so they don't develop the joint and heart issues associated with heavy weight gain.
If you want to keep them strictly as pets, they'd still need to be kept apart from the other chicks as they'd need a restricted diet and encouraged to exercise, to keep their weight as light as possible so they don't develop the joint and heart issues associated with heavy weight gain.