You can list any account, even if you don't own it.
You could even list @elonmusk — as long as it's not already listed.
If you add an account owned by someone else, interest will begin to accrue to their wallet immediately, and they can claim it anytime.
We highly recommend that you List & Buy when listing a new token.
This is because when you list a new token, it starts at the lowest possible price. If you don't List & Buy in the same transaction, you might lose the opportunity to buy at the moment of minimum risk and maximum potential reward.