The last time I fooled with Black Hole it was still a click power that phases enemies for a fixed duration. Wormhole, as I recall, became a targeted toggle when Gravity got a minor revamp that introduced impact damage. To my knowledge, they currently behave differently with Black Hole still being very unwieldy.
Rules for multi-boxing are found under the Code of Conduct. It's generally ok to a limited number of accounts under certain server populations, but it's the player's responsibility to watch the population and log out accounts if there population threshold is crossed.