Well it's about time I commented again on my own thread. I'm glad to see I'm not the only one who feels objectives need a bit of work.
With Slaughter, I can see why people are dropping it, but for me the strongest argument showing something isn't right, are the requirements to get 4VP's compared to assassination. i.e. Kill just the master vs. Kill the master and the entire crew. It doesn't matter how good your collection and selection skills are, or when you get to choose your crew, slaughter has significantly higher requirements than assassinate.
I also like the idea of negative VP's in an announced scheme. It reminds me of the subplots in Battlefleet Gothic (GW's space game). They were the equivalent of a randomly generated scheme and had variable 'renown' rewards (and penalties).
Currently, in Malifaux, there's no reason not to take schemes and little reason to keep them secret, so increasing the risk/reward level on them forces players to think about whether they want to take them and whether they want to anounce them.