If you are interested in fights, want to earn money easily and you don't want to damage your reputation you should think about raids. In order to do that you should have at least a team consisting of three characters and two or more turrets on both sides of your train. When you do that you can attack. Who? Civilian camps are your best target - attacking them is harmless and most of the camps are independent. Natives can also be an option - you don't have much to do with them. Ultimately, you can attack bandits (it is easier to get your reputation back if you need).