For the contract: On second thought, I would actually twist it around.

Contract: When a Mercenary vows to achieve a task (usually in return for money), little can keep him from his task. He recieves a lesser geas, with no HD limit applied, related to his task.

There. It pulls away from the GP cost, but on second thought, I don't think it works that well- a mercenary should be able to set his own prices. There are issues where the mercenary can give back the cost, but I suspect trying to limit them (I had considered a thing where you have to measure the balance of money between people for all things) wouldn't work out well (suppose a Mercenary player accepted a smaller share of money from the loot, for example). The price paid is agreed upon between people depending on the value of the service.

What's important about this is that it mechanically distinguishes On A Job from Not On A Job, which was what I wanted in the first place.

On maneuvers: I wouldn't tie them to combat styles- I'd probably give some level of free choice (perhaps powered by Martial Study, plus an innate ability to refresh Martial Study-granted maneuvers?)