YMMV
Grading is very subjective even tho the criteria are "standardized". Some instructors hand out 5's like candy while some make you work for MIF. I felt that I was graded pretty fairly for my performance, but I definitely would've done better in forms had I not been scheduled for a CCX.
The minimum NSS for strike is a 50 for Navy and a 52 for Marines; if you study hard and fly well, you can certainly get it. Disclaimer: NSS is not necessarily a reflection of pilot performance, it's a number that describes your performance relative to past completers in the squadron
That being said, the best piece of advice I can give is just control what you're able to control. You can't control the schedule, but you can certainly control your flight prep and your health.