Child Passport Renewal from Abroad

Hello

When applying for child UK passport renewal from abroad,

1 - Do we get the old passport back as it will have valid Visa for the country where we are staying?

2 - How long before expiry can we apply for a renewal ?

3 - Except for child appearance (natural change from birth to age 5 years) and residential address, nothing else (such as name) has changed. This will be considered as a renewal, correct ?

Thank-you!!!