[quote=@deegee]
I love the idea of a heist. On a train? Maybe. But I also love the notion of a payroll heist that necessitates getting into someplace they shouldn't be in the first place. In town? In the Big Bad's stately home? In addition to this, I like the idea of coming to learn a little of the town, what makes BBEG deserve his title.
[/quote]

I have two proposals for the Bad Guy and his relation to the main character: BBEG is a railroad/mining/space dust/whatever magnate, that keeps the local town under his thumb with his hired goons. The Protagonist used to be his right-hand-man, his troubleshooter and enforcer, before The Tycoon crossed a moral line that forced the now-Repentant gunslinger to grow a spine and a conscience. Left for dead and filled with guilt for his past wrongs, the Repentant gathers strength and allies to hit back. Perhaps, like in [i]Pale Rider[/i], he comes to the aid of an outlying community of people the Tycoon wants to run off. After beating back his initial thugs, the Repentant leads his ragtag team of downtrodden townies and hired allies on the offensive, planning to hit a gold/payroll/uranium/magic-space-healing-plant shipment. They Tycoon doesn't take this lying down, calling in the best, meanest troubleshooters money can buy from out of town. Big themes: Guilt, Atonement, Justice, Corruption.

The other concept I had goes something like this: Your kid brother hit it big out west. Gold, Oil, Cattle, whatever. You were happy for him, watching him build a name (and a town) for himself. But then a woman got off a train from the east and wrapped him around her finger. You could tell from the start she was no good, but your brother - God rest him - was naive about these sort of things. She whispered poison in his ears and drove a wedge between you. Unfortunately, it would seem she was not only a gold digger, but a black widow too; not long after they were wed, your brother dies suspiciously. The town comes under the iron grip of her pristinely-painted fingers, and devolves into a den of fraud, oppression, and vice.  For your brother's sake, you're going to make her pay, and there's plenty of disaffected townies that - if they could be made to grow a spine - would like to see her go down as well.