1) So yes -- the General was upset at his own lack of capabilities to protect Su JiuQing and took it out on her....that happens...a lot in human interactions. Nobody's perfect lol.
2) No matter the time period, it's gonna be extremely hard, complicated, and expensive to uproot your entire life and family so you can just run away from your problems. And it's gonna be even harder to travel without hired security as women (if Su JiuQing just runs away with her mom) ANND to a place that may not economically or physically developed during this time period. Being a refugee hasn't been all fun & games the last time I saw in the news

3) Even if she ran away, during this time, she needs to make a living to provide for family. If she decides to open up another shop, she gonna need start up money, and someone to get supplies, and probably a benefactor so people don't think she's a quack
No character is perfect, but that's why I like this series. It's based on a regular person that's just trying to live life with some extra knowledge and experience. There's a lot of other stuff I would like to say, but thank you for coming to my TedTalk lol xD