Ralph has autism spectrum disorder or Asperger Syndrome.
It is established in the game that Ralph displays an immense aptitude for cars, but is looked down upon by Salieri and the others as a "complete idiot" or a "moron" when it comes to everything else. Since people with Aspergers may display repetitive or a narrow set of interests, converse mostly about their favourite things and tend to be clumsy, it seems to line up with Ralph's focus on cars and social awkwardness. Though despite his awkward interactions with others, he is shown in the remake to have built up a pent-up sense of contempt towards those who bullied him especially Paulie whom he threatened to sabotage his car behind his back. And since awareness of autism spectrum disorders aren't as much in the 1930s as it is today, it's easy for Ralph to be dismissed and bullied upon due to his condition—the mission "Better Get Used To It" has Ralphie mention that part of the reason why he came to work with Salieri was to avoid being bullied by the same hoodlums who nearly raped Sarah. Sarah and her daughter will join or start an antimafia movement.
Given Tommy's brutal death in the hands of Vito and Joe, and since there is still the possibility of the Salieris going after Tommy's family as well due to how they also took care of not just Frank but his wife and daughter, the now-widowed Sarah and her daughter may as well either join or start an antimafia advocacy group to further shield them from mob retaliation than just witness protection alone, similar to how Sonia Alfano became president of an association for the families of Mafia victims as his father was murdered by the Sicilian mob in 1993.note The Freeride modes are Tommy's afterlife.
Or they could be a some sort of dreamworld Tommy enters into following him being shot down in the epilogue. In this world he is damned to wander a recreation of Lost Heaven and still operating as a mobster, and could account for the more bizarre situations such as chasing invisible men, coming across a sea monster and meeting aliens, which in no way fits the main narrative. Case in point in the remake where he does jobs for Henry Baskerville, a man with the head of a German Shepherd dog. Sam is a relative of Aldo Trapani from The Godfather video game.
In the remake Sam's surname is revealed to be Trapani, which he shares with Aldo. Tommy survived the shooting at the end ofMafia: Definitive Edition.
Unlike the original game and Mafia II where he was outright killed, Tommy may have survived. Now that he is presumed dead and thanks to a majority of the mobsters in Empire Bay being wiped out thanks to Vito and Joe in Mafia II, Tommy can now undergo a new name elsewhere and properly settle down with his family.