So if I go into a shootout with the postal worker is it just me versus her and if I have one gun card I win? or do all the players have to throw down their gun cards?
The way the rules are written all the other players CAN throw down a gun card. This means that if you get in a shootout with a postal worker (or anyone in the post office for that matter) you will start the shootout and that your opponents can play as the victim and have the shootout with you.