i had a blue spot puffer in my 45, with about 4 other shrimp, and it never touched a thing. i never really had any corals, so i have no clue how it takes to those, but out of all the puffers i would say that this is the most peaceful/
No puffer is guaranteed to be reef-safe, but most of the toby/sharpnose puffers (like the Blue-Spot and Valentini) are generally reef-safe. They'll pick on your small hermits, and maybe a few snails. I have a Coral-Banded Shrimp that no one messes with, but I couldn't tell you how the smaller puffers are with other shrimp.
I would be real careful there. I have a foxface that pics on the reef all the time, really does not do any damage, but he could if he wanted. I find if you keep them fed good, you don't have to worry much about it.
mine messes with everything, (dogface) the first thing he did when he went into the tank was destroy some plants that were based on the live rock. Snails, shrimp, and hermits are all gone, except for 1 snail who has some how been overlooked.
usually there not good candidates for coral reef tanks because they pick at coral when they're hungry etc..
but it all depends on the personality of the fish too.
I even had a cleaner shrimp pick at one of my soft corals till it died and i believe everywhere it says they're reef safe.