I have two Electric Blue Hermits and have had no problems with them. There is no aggression with them, and I often find them tucked in a cave with my Fire Shrimp. I always make sure they are well fed by target feeding them with half a prawn each once a week.
I have one of these guys and he is great. 100% peaceful won't bother any of the other tank inhabitants including snails and a fellow hermit crab, despite his large demeanor. Also a hard-working scavenger!