Scoby is quiet, shiftless, and he nods a lot. He is a friend of Slow Joe, and generally goes along with whatever Slow Joe tells him, but Scoby is not really evil. He was a janitor in prison and the guards beat him up for fun. He wants to leave Denver but doesn't want to return west, as there is nothing for him there.
Before he was incarcerated he was occasionally recruited by J.J. Morehouse to disable tracks on the NCR railway project so Morehouse could demand more supplies and better pay for the team.
Not dealing with the traitor Salvagers before attempting to explore the Box will, in a cut scene, result in a violent conflict as the traitors turn up looking to take it for themselves. If Bombay Jack also wasn't dealt with it will include him detonating the bombs in his base in an attempt to take everyone else out with him. The Prisoner and any companions will be scattered around the rubble alive but severely injured.
If the Prisoner puts off exploring the Box for long enough, the traitor Salvagers will go ahead with their plan to strike it. The Prisoner will hear their interactions over a radio and may be able to get their before the showdown if he is quick. If not, he will reach the Box only to find that Jack was able to snipe or bomb all of them and will already be stripping their corpses, he will already have done this too if the Prisoner puts off investigation even longer.