I respect your opinion, but I disagree with that!
Yes you're right about the hired companions, that's not worth it. But Gris, Hirge and Adaon are really helpful and won't die (they revive).
About the difficulty, that discussion is not new, we talked about it several times and for n players there are about 2^n opinions to that topic
My opinion: I like the difficulty levels, well yes I would like to save on hard inside a dungeon, but that's the only point that bothers me.
Causal is easy, but only if you get how to play the game. What you want is more like a story mode, I'm against that, but I'm only a player and that's only my opinion. I play a lot of RPG games and EK is one of few where I spend a lot of time because of the difficulty. There is always some space to improve or to learn how you can solve something 'better'. That's what I love about that game and the main reason why I didn't quit after the first run. But that's my opinion, I'm not the developer and my vote doesn't count more than yours.