Why is the story so messed up?

I've only watched 2 episodes, but I don't get why the queen is freaking out after hearing they're taking concubines. Isn't the fundamental core reason for a queen's existence to produce an heir? Even if I overlook that, I don't get why she'd try to escape to go to her territory. If you're the queen, you should expect to be confined within the palace walls. If you really want to, try finding another way to communicate. I also don't get why the servant would try to betray her after she confided in them. Even if she doesn't get good treatment from her husband, attempting to assassinate the queen? Does she want her entire family wiped out? Doesn't she consider her own powerful family? And the escape method, trying to climb down with curtains, they'd stop her immediately, right? I don't get it.