I assumed that the buff from the priest was just for passing all the checks well, and making a good dedication of it - I always strip down anyway, because it felt appropriate.
The game provides you an option to get the brand, and the items do describe that they negatively impact those not marked by the absolute - I wouldn't' have said that was really out of the way or hidden, personally, and it certainly doesn't require forum trawling.
Who are you thinking of in terms of NPCs predisposed to dying? Next play through I'm going to sneak into the grove ahead of the first attack and try to speak to him, to see if he's actually got dialogue.
I pretty much always kill the commander and his two cambion allies, in the nautilod - you don't get XP for him, but you get a lot for them; you get enough to get to level 2 before activating the transponder, in fact, and it feel very much like the ship in D:OS2, wherein if you scraped every bit of XP you could get just right, you got to level 2 before you hit the beach... it's almost identical in that respect.
One thing I'm looking at exploring soon is to let the Ilithid eat my brain, then revive the character with my allies and continue on... so that he's very definitely alive, come the goblin came scenes.
