i put 20 blue legged hermits every other month when the lights are out. most get eaten and get picked when the lights come on. but some survive and learn to scavenge in the dark..i read that a queen or a fighting conch can be used for aggressive tanks..
what kind of damsels???? since it is a large tank add the hawkfishes first. try to get the triggers as small as you can and introduce them last after all the other fishies are established in the tank.
there are alot who just use lr, powerheads, and water changes..even though not needed on most systems, it is good practice to use skimmers...activated carbon and some type of floss material for waste should be used also..
all inverts are sensitive to salinity and temp. check the salinity in the bag and slowly try to match it to the tanks. slowly as in 30-45minutes. then just place them in the tank..
it would be coool...but it might sound like a waterfall at first..and you have to get used to the humming from the pumps...once you get used to the noises, the sounds should put you right to sleep.