Regarding Divine Sense:
Yes indeed, I'm reading the 5e version around specifically celestial, fiend, or undead. Mostly I just wasn't sure that I'd use this ability very often but then remembered Fay had an usual run in with a feeling of strong evil, so I figured I'd use it. I'll try it a few times as we get deeper into the cave, especially where Fay just pointed. There's also the chance at the locations of desecration.
Regarding the 'powerful good' side of things, I was also curious to see if anyone in the party struck Velon as particularly good! (Laugh).
Basically, the way I interpret it, Divine sense lets you pick up the presence of energy from the good and evil aligned planes. So while Lia and Geoffroy won't 'ping' for you right now, they might if channeling a powerful divine spell/ability. You might also sense Onwen if he is in the midst of channeling one of the stronger necromatic spells he knows (Raise dead and its ilk in particular).
Thanks, yeah, makes sense now! The only thing that's difficult going forward is keeping track of the different damage dice since I've created a weird combo of Green Flame Blade and potential Smite damage, never mind when I decide to use sorcery points.
I love that just about the whole party gets bonus to hit via multiple Bless spells. Hopefully we're quite the deadly unit!