Firstly, I love F13 a lot. I've been addicted to it since beta and I've been going at it nonstop since launch. Thanks for a great game.
I really like a lot of these ideas:
Having to do a QTE to get out of Jason's grab sounds really interesting. I think it'd be cool if they had a certain amount of time to escape the grab before Jason can get an execution instead of just being a meter that automatically fills up. You could have it based on composure instead of repair and it would be a fun little mini-game instead of just mashing the 'e' button or getting killed instantly.
I think this would also encourage Jason to enter combat mode if he's outnumbered against a lot of counselors, since now there would be a time limit and he'd easily be forced to let a counselor go. You could probably shorten the timer based on how injured or afraid they are, just to give him an edge against people he's been harrassing.
Melee spam kills have also been a pretty big issue for a lot of people, though it's fun when you run into Jasons that don't expect you to block and retaliate. I think punishing Jason for a whiffed or blocked attack seems fair, just a small stutter to help counselors make a decision. I understand that Jason should be intimidating and he very often instantly murdered people in the movies, but from a gameplay standpoint it would be more fun to have the counselors contest him and be at more of a disadvantage due to their fear and condition. I've never lost more than one survivor so far playing as Jason and it'd be nice to see some 'cat and mouse' playstyle encouraged. Those games are always the most fun.
Lemme know how you guys feel about these changes.