As entertainment the movie was decent. But in my opinion it's just one bullshit story after another like him killing the Nino Gaggi character in the movie.
As far as i know there is no proof the Iceman even knew DeMeo let alone killed for him. Yes he was probably at the Gemini a few times but so were alot of other people. I don't believe Roy ever used him for any hit. He just tried hitching his wagon to DeMeo's in my opinion for the extra hitman cred. No doubt Kuklinski was a killer but i think they were all local guys he was doing business with or had a grudge against.
At the end of the movie it said something like foul play was suspected in Kuklinski's death after he named a former Gambino underboss in a murder case. Who would give a shit about Gravano being framed? Nobody. If anything they would of loved to see Sammy go down on a bullshit story like the Iceman most likely made up.
Definitely on the last part. Dr. Michael Baden who is one of the world's leading pathologists examined him and said he died of natural causes. That was pretty goofy of them to put in there. As far as I can tell there was nothing remotely suspicious about his death.
