Cross posting my response incase anyone has similar questions or thoughts.
Thanks Steve Hickey!
Emotions: We'll absolutely playtest a few games with persistent emotions and see how it plays out.
Centering: Your Emotional State is always a d8 like your second example. So the d8/d6s move around the spectrum.
Failure: We hadn't considered that. I could see a case for "flipping" I might try it as a strength and if it plays well consider including it.
Exploding: I feel like I'd want to bake that into the players narration so we don't have to stop each time the die explodes. It might slow down the resolution a bit much.
Thank you for the feedback!