The fact that so many cutscenes are tied to long resting shouldn't be used to argue against (or for) a proposed resting system. There are a total of what, 4 cutscenes that actually require a long rest? The dream sequence(s?), Astarion, Lae'zel trying to kill you, and the post-grove-raid party. All others could be changed to: "next time you visit camp" or "next time you talk with a character" or even "next time you short rest."
We're proposing change here, so unless you actively like so many cutscenes being tied only to long resting, it shouldn't really weigh into discussions because the "cutscene upon rest" mechanic can also be changed.
I like the idea of there being restrictions to long resting, especially
For example, for each 10 points over 100, you'd get a -1 on any roll you make. That again makes roleplaying sense, it's harder to fight or lie convincingly if you're dead tired. Personally, I'm also fine without that.
A simpler (and more obvious that it's rest-related) solution would be levels of exhaustion. Change it to every 15-25 points over 100 because the levels of exhaustion are so much more punishing than a -1 penalty (1st level = disadvantage on all ability checks).
However, your system is a bit strict. It might be better to allow resting at <100 points (but above 50), but then your impatient companions would yell at you and maybe give slight disapproval. This allows people to rest frequently if they want and are willing to accept Lae'zel's unhappiness, but encourages them to push on.
