Repeatedly leaving or disconnecting from games will add a leaver status to an account.
Information on using the same Battle.net Authenticator on more than one Battle.net account
Information about how to unlink your Activision account from your Battle.net account
How to unlink your Twitch account from your Battle.net account
Steps for linking an Activision account and Call of Duty Profile to your Battle.net Account.
What to do if you need to unlink your Activision account from your Battle.net account
The Blizzard End User License Agreement explains what you may and may not do with a Blizzard account. This article highlights a few passages from the EULA that are most relevant to this policy.