As for "Hearts", I'm disappointed that they tend to lock-out content after finishing them.
The Norn area south-east of Vigil HQ for example.
There's an arena and cages where you can fight monsters and stuff to "prove your skills".
So I did the solo-monsters until I got the heart filled.
Wanted to go into the group-battle arena, but it was all "NOPE! You've proven yourself already so there's no need to!".