No, Marilyn Manson did not really have some of his ribs removed, that is a false rumor.
Marilyn Manson (band), Nine Inch Nails, Ozzy Osbourne, Rob Zombie, Mrs. Scabtree, Jack Off Jill
Brian Hugh Warner (born January 5, 1969), better known by his stage name Marilyn Manson, is an American musician, actor, painter, multimedia artist and former music journalist known for his controversial stage personality and image as the eponymous lead singer of the band Marilyn Manson, of which he is the founder and only constant member. His stage name was formed by juxtaposing the names of two American cultural icons, namely actress Marilyn Monroe and multiple murder conspiracy convict Charles Manson. Music
Charles Milles Manson (born November 12, 1934) is an American criminal and musician who led what became known as the Manson Family, a quasi-commune that arose in California in the late 1960s. He was found guilty of conspiracy to commit the murders of Sharon Tate and Leno and Rosemary LaBianca carried out by members of the group at his instruction. He was convicted of the murders through the joint-responsibility rule, which makes each member of a conspiracy guilty of crimes his fellow conspirators commit in furtherance of the conspiracy's objective.
Manson believed in what he called "Helter Skelter", a term he took from the song of the same name by the Beatles. Manson believed Helter Skelter to be an impending apocalyptic race war, which he described in his own version of the lyrics to the Beatles' song. He believed his murders would help precipitate that war. From the beginning of his notoriety, a pop culture arose around him in which he ultimately became an emblem of insanity, violence and the macabre. The term "helter skelter" was later used by Manson prosecutor Vincent Bugliosi as the title of a book that he wrote about the Manson murders. MarilynManson.com