I just want to say to those playing for first time, even though tutorial gives you a hint on how you should focus on certain skills since you can't pass everything, just know there are skills you are going to need improve regardless of the route you are going after. I am not going to say which ones since that will be a spoiler, but when playing pay attention to what is happening in game and judge what you think may be important to improve.
Haha i am giving this little advice because it is pain having to restart tons of times due to deaths xD I playing on adventure mode for first time btw, so I expected this anyway :p
and just as another hint if I wasn't already clear, every skill for both main character and princes all have uses. This game was very well designed , especially for an otome type game. unlike certain other games i rather not mention and rant about here, your skills and decisions actually make a meaningful impact in what happens in the story. I won't say like it will turn the whole story around, i don't think anything thaat dramatic, but without spoiling too much, your choices have purpose. This is not one of the visual novel type games where you choose something and it barely impacts the narrative of the story.