your blue legs will probably whack your red leg hermits.
i have 5 snails and 5 red legs in my tank. 3 of the snails came off of the glass and onto the sand heading towards the rocks, and they got "shell-jacked"
A good rule of thumb would be to go with the reef packages on this site. I would be careful of the brittle and serpent stars though. If you don't target feed them they will ambush your fish.
yeah I had a good deal of shell-jcaking that went down and there is a good bit of batteling between the hermits but have yet to loose any to it. and they are all molting like crazy... At first thought they were dieing but kept a count and realized I found more bodies then hermits I owned. anyway when they molt should you remove the molt or leave it? many times its between the rocks and I cant get to it... I think I just hijacked my own thread