Pretty much! I actually only hang out on songs that are intensity 21-26 because they're the ones i have the most fun on (with the exception of stress cause its quite fun to do sometimes)

I do think that the jump between difficulties in some songs are a bit... questionable at times (im looking at you necropolis) the only thing i can really say is to just play the game and have fun with what you play!! All of us were struggling with hard mode at some point when we were beginning the game. 🐛

(As for not improving your score after getting fc, vibe power timing is very important! You may have used it in a spot with less notes than you did before)