Is it against the terms of use, to share account?

If you are thinking of sharing an account to reach rank 14 by playing 24h a day just dont do it.

First of all other high pvp players will notice and report you and then it is a matter of time to get banned.

Just play by the rules. I have never done anything fishy during so many years of wow and I neved felt bad for not taking advatage of various exploits and other stuff.

Enjoy the game as it is ment to be done in a fair way. That way, it is more satisfying.