I can honestly see Past Sins being the plot-line in MLP:FiM-The movie. That is, if it ever happens.
If Faust ever picked up on the idea she may see the part where Twilight gets hanged as... problematic since any piece of media for kids these days has to be COMPLETELY safe for them. This mean no kids smoking cigars like in Pinocchio, no murder and revenge stories like the Lion King, and other crazy stuff like a prince kissing a dead lady named Snow White. Besides that its perfect.