Being aggressive is Bigby's job. I didn't read comics but he doesn't hit weak ones like women and children(so far), and he never hurt Snow.
Being aggressive to scumbags like george, bluebeard, woody, dum and dee, ...is that really a problem? and not looking for holy's sister was Snow's fault. She does the paper works, decides which task should be done, so, Bigby is not to be blamed.
Snow always makes it clear that she is not happy with Bigby's violent nature, but other fables are not much saints either, they shot Bigby, attacked him nearly to death, swung ax at him, beat him, and many of them are selfish jerks who don't deserve much respect. (cold-hearted pimp, thief, liar, slacker, rich sociopath, etc,.)
Bigby SHOULD be a bit violent to control this shabby fable town. What's he gonna do when woody jump on him with bloody ax? quickly dodge and say 'thx for your cooperation.'?
Why can't I kill d*** after he shot me about dozen times? Why not? They tried to kill Bigby.