i remember the murder of the waiter. that i thought was one of the worst events in this show. it didn't make sense. it was sloppy as hell. in my opinion it was a way for the writers to form a truce between paulie and CM.
The scene served a purpose. It showed that these guys are really petty and not particularly bright.
A lot of their alliances are based on common experiences (they may have killed someone together, for instance).