I really like this idea.. I probably don't know the rules well enough to be able to help but...
I have noticed that several threads on various sites that refer to army list creators that have the words "army" and "builder" together in the title have had to be removed because of copyright issues with that company that makes armybuilder.
I want to make this a positive and get you to come up with a better name for your project... builder is so tired and does not fit the theme of Malifaux anyway..
Maybe "Crew Creator" or "Hired Gun Saloon" or something that has a link to the western, steampunk or victorian eras.