User blog comment:Zathronas/Analysis by an author: Volume 2 episode 9: Search and Destroy/@comment-23.239.47.154-20141003130704/@comment-23.239.47.154-20141003141409

Wiess shown in Vol. 1 chapter 15 the stray and Vol. 2  chapter 3 don't have much liking of her family, Wiess may as well became a huntress to get some breathing space.

If Blake become a hero in the humans eyes would do alot for the faunus plight.

One of the things a hunter does is move to places to places protecting them from grimm giving Yang a excuse to look for her real mom, it is hinted that she didn't want to be on the same team as Ruby so that she can look for her mom without worring about litting sister.