Wow, I sure hope it is a molt. I looked all over the tank and can only count one though. They do hide very well, so hoping for the best!
As for acclimating, I followed the LFS
directions. Float bag in tank for 20 min, then add a little tank water, then wait, then a little more, then wait. etc. Took about 45 min or so before I put them in.
I also had one of those tentacle things growing on my live rock, pretty big, I guess they are the nuisance guys that sting corals and such. Well, a couple days after adding the shrimp, this was gone. I hope my guy didn't get sick and die from eating it!