Saltwater tank questions. Starfish and hermit crabs together?

I recently purchased 3 hermit crabs, 1 emerald crab, 1 scooter blenny and 1 red starfish. I read online that they are all nonaggresive for the most part, the starfish being the most preditorial. The more I read, the more I realize this may not have been a good idea. Any idea who will go first? I also have a damsel and snail in the tank. The damsel seems to be getting along fine with everyone so far. i also plan on getting some clownfish and Yellow tang in the future along w some scallops. Any advice? I really hope the starfish doesnt eat anyone. same with the baby hermit crabs. Will the scooter blenny eat anyone? Its a fairly large tank. Im probably just stressing about it bc its my first time w saltwater