Do you HAVE to use Game Center in Unity?

I'm building my Xcode which is fine unless I disable Game Center then I get all sort of build errors. Presumably Unity links to the GameKit library. Does this mean you HAVE to use game kit?
Does this mean you have to enable Game Center in your App ID?

Also, if you don't use any of the game centre functionality won't your app get rejected?

So thats really 3 questions:

1) Any way to disable Game Center in Xcode Capabilities without getting link errors?
2) If I leave it enabled but not have...

Do you HAVE to use Game Center in Unity?