Alright. This will be the last thing I say about this.
I don't know. I haven't seen the game. I don't know how it plays, I don't know the difficulty curve, I'm not sure how I feel about all this. In the end, I want a fair game that challenges me when called for. Maybe the new rules make sense and I'll get used to them. In that case, fair enough. And perhaps not. And in that case, I will probably mod it in, that mod will be there super fast - as the game already lets you walk around naked [I think, what else are the genitals for?]. Not what I hoped for, but I suspect it's what I would want.
But, my gut says, Core Rules, even if it's only optional so it's casual for the casuals.
But. If you give others the options to do whatever, then whatever should include being able to play by the rules and be restricted in their choices. Choice and consequence in an RPG matters just as much in dialogue as it does when progressing your character.
I would *always* check the Core Rules button if it's there. *Always*, even if it becomes annoyingly hard and Tav loses an arm or a tentacle. Core Rules setting will affect my experience positively for the entire game.