1) I can see why Rocco would want to get as close to Mike as Neri, but if he thought the Roth assassination in the airport was the way to do it, he must have had closeness in the afterlife in mind. Surely Rocco must have known that there was no way that he would ever escape from the airport.
Michael, the old manipulator, gave Rocco no choice. Put yourself in his shoes:
--In the boathouse, Neri reclines in the chair and leads the discussion on Roth. Rocco stands guard, like the security guard he's become (when he's not a waiter, feeding Johnny Ola's men).
--After Michael brutally humiliated Tom about his job offer and mistress (watch Neri smirk; he was obviously the source of that info), he then says he wants Roth's plane met.
--Tom, true to form, falls right back into character: "Impossible...like assassinating the President." Sets stage for another humiliation: "Y'know, Tom, you surprise me...if there's one thing that's certain...it's that you can kill anyone."
--And then Michael turns and says, "Rocco?"
He doesn't say, "Al?" He says, "Rocco?"Now, what's Rocco going to say? "Uh, Mike, uh, I agree with Tom: impossible"?? After Tom was humiliated giving the "impossible" answer? Not a chance! Michael gave him no options.