I am from Providence, and follow the Friars consistently. Marshon Brooks would not be a good fit in the Celtics system, and I don't think he is going to be a multi-year All-Star. He's not that great of a player, honestly, despite your bizarre claims that every one of his points was contested. I am not even entirely sure if you have ever watched a Friars game, based on what you are saying in this thread.
He is a good shooter, yes, but his game is not ready for the NBA. All he really did in college was run iso plays, and he is no good off the ball. In this year's draft class he had the third lowest percentage of catch-and-shoot opportunities, which is indicative of his style of play. Most of his point come off contested jumpers; yeah, he had a good senior year draining these, but in the NBA the defense will be tougher and his horrible shot selection will catch up to him. He needs to make a lot of adjustments to play in the NBA. He has awful court vision, is a mediocre passer, and is not a good defensive player. You can prattle all you want about the Friars system, but that only goes for team defense. His man-on-man effort is lackluster, and he is really bad about getting back to his end of the court (loves admiring his own baskets, which isn't good in the NBA).
Remember, this kid was a 2nd round projection until the combine, and only rose due to having a good athletic showing. An NBA star that does not make. He is going to be a Nick Young or Jordan Crawford level contributor, at best.