Not sure if this deck is good. It's probably not. But I built it and then immediately went on a hot streak through Diamond 1 up to Master. Its tuned to deal with the endless aggro and FJS decks that I was facing. If you're facing different decks then change the cards that aren't good in those matchups.
Oh, and Mug is technically meant to be a way to punish FJS for making the exact same sequence every game as if there is literally no other option: Merchant for Tomb, play Tomb, Sabotage. Mug is the preemptive answer to that line, which is easy because FJS players are the most predictable players ever.