Another M15 card I've been considering for Marchesa is Chasm Skulker. Leaves some guys after it dies and those can be sacrificed or grown if we attack with them. Still not sure what I'd cut for it though.
I've been playing a similar build and Hall of the Bandit Lord has been a great card if I can't get Anger or Urabrask the Hidden out. It's particularly effective if I can use it the first time I cast Marchesa, the Black Rose since she'll come down and generally immediately be able to get a counter. In the later stages of the game, it can be an outlet to drop your life if you really need to.
Thanks for the great insight on your build!