Nano,
There are some mushrooms here in Hawaii that have been introduced. However, I don't think it is a good idea to spread the whereabouts of these corals around. Spreading them might increase their chance of establishing. Also, there still might be legal concerns with maintaining these corals (which the State takes very seriously). Other than that, if you decide to maintain any soft corals, just be very careful how you take them. The State is aware of this loop hole, and they will eventually fix it.
As far as the Waikiki Aquarium, they obtain there water from two sources (ocean and well). The discharge on tanks with South Pacific corals goes into the municipal sewer. They also have all the required permits to bring in most type of corals, and the appropriate permit for sewer discharge.
Also, I don't recommend trying to import corals. If you get caught, the penalities are steep. Then we can all enjoy your corals when they are given to the Waikiki Aquarium. Just my 2 cents.
Aloha
Tony