1: To a degree, though only the devs know how much. The balancing I’ve seen so far is like this: a background like the swordmaster is rare and powerful, but comes with its own drawbacks and you need to put effort into making the most of him. He is also expensive and there’s always a chance of him having poor stats or traits, so you need to weigh your options. Similarly, a cheap recruit will usually be bad but might turn out to have good stats and traits. The game therefore seems to avoid straight upgrades and there is always a use for weaker tools or recruits, with weaker tools being cheaper and making for good backup weapons if you break all your expensive ones.
2: Yes, the traits a character can get and their odds of getting them depend on which background they have.
