I have seen Zhang Jingyi in another drama (Fall in Love) where she also plays a strong female lead. I really loved it, she has this ability to play a smart female character!
As for their romance, I am really looking forward. TBH, I usually skip the school/teaching part and the business drama ones. I enjoy the political and the unsolved mystery (Grandmother and the Empress, the burned house, the conflict with the Yanxi family etc). I just can't wait for their romance to fully develop. I really like how Yanxi helps Hua Zhi in more subtle way, she usually seeks advice from him and also a shoulder to lean on. You can really feel like they had a deeper connection instantly from early on.
Hua Zhi showed how mature she is in Episode 16 and this is just the beginning. I hope the screenwriter and director did not change her character later on!