Look I doubt that there was a thief (Bill) a Rat (?) and Shooter (?)! I am going with the Rat and the shooter being the same damn person. And the only charecter that makes sense is the new guy that was just added to the story Steve. Steve wanted to refuse guard duty (Because Pip' would recognize him and blow his cover).

THe only recourse that the Rat (Steve!) had is inaction or take out the threat.
Inaction: Steve would eventually run into Pippin either when it came to light that Pippin poses no threat or the off chance that people stopped buying his BS excuses to get out of guard duty and thus being exposed to Pip'.
Take Out the Threat: The only option that still allows the Rat to have the initiative. If taking out Pip works then he is back in buisness, if it doesn't work then he still has the ability to leave on his own terms either way this is the only way that lets Steve carry out his original mission, Gathering intelegence and sowing discord (such as stirring the pot and getting Lizzy booted).

I still haven't noticed the "sniff" at the end of the episode but if there is one I'm thinking that maybe Steve was spritzing some cologne into the room so frame Vic and get them off of his back.
And I think the shooting of the CB Radio idea is excessive... Honestly I think that Hope was purosfully wounded and left to smell "Victor" and let Steve get away with it