Do you have to set up an additional account for a second controller to play alongside ...

Hi

The guest account facility may suit your requirements. Please see the link below for information about guest accounts.

http://support.xbox.com/my-account/security/use-guest-account

Your account is a Silver account. You need a Gold membership in order to play on Live. This will be why you cannot set up the second controller as a guest.

I'm happy with my Limited Edition Titanfall controller for my second controller alongside my Day One Edition controller!

If you have an additional controller, you could try signing into your primary account with the second controller. As long as that account is signed in, you should have access to the licenses associated with that account. If I recall correctly, you can have
a secondary account online, but not actively playing the game. That may solve the problem until you can preform a license transfer again.

You'll want to look at the Family & Online Safety section of the Microsoft help center:

https://beta.support.xbox.com/help/family-online-safety/browse

Basically, you'll have to create a second account, so you and your son both have your own account, and then you set up a Family on your account and add your son to the family.

When you are signed into the Xbox on one controller, you can sign into the second account from the second controller by pressing the Xbox Guide button on the controller to bring up the sidebar. On the accounts tab you can choose to sign in as a guest to
your account or as the second account that you create.