The porcelain Crab I am not sure about.. The emerald crab should be ok.. I have heard of a few ppl having issues with them but not many.. They say they are reef safe so id go with it.. As for crabs being pretty hardy i would say that most are.. I have about 15 or so unidentified crabs that came is as hitchhikers into a new tank and so far they have been just fine.. I found one that fell onto the floor 5 hours after I got the LR
and threw him into the tank and he ran off like it was no big deal.. If they made it thru the transport I would say that they should make it anywhere lol... JMHO
my liverock came overnight from Florida.. I found 2 or 3 deal crabs out of like 15 or so...