I also have green spotted puffer or GSP. The problem with these little buggers is that they are very unpredicatable like all fish that we get. Some can co-habitat with others and some are viscious lil guys. You should have no problem using live rock, they wont bother that at all. It's everything else that moves. I have seen people with mutiple tankmates in with the GSP with no problems. This doesn't mean that down the road you wont have a problem. Just like mine he is always buzzing around the tank, greets me at the glass when I come home, but you never know with these guys, very unpredicatble...you could have a tank full of nice fish at night...and wake up in the morning and he'll be buzzing around with a smile....and a fin hanging out his mouth and no other fish.
So to really answer your question can he be kept with live rock or other animals...yes and with caution...yes to the live rock but with other tankmates i would say with caution...
All in all...great fish to have, just like a puppy...I love mine.