I don't know I guess I'm just scared that the examiners are going to be REALLY picky and that kids who get 8/10 in exams are really high end students (averaging 90-95% in sacs)
And is it true that examiners have the preconvinced idea that expository essays are boring and that's why they get low marks? I'm really not that creative and I love expository essays because I like essays which have some sort of structure.
I averaged low 80s in my SACs, and I wouldn't say we had a very strong cohort. I then didn't do much extra work between the end of SACs and the exam due to panic, and yet got a 43, which would imply probably ~8-8.5s across the exam. Not saying that you shouldn't work or are certain to get 8s, but that you really do have a chance if you keep up the good work. Just keep getting feedback and trying to constantly improve

No; if you hit the criteria (good ideas, good writing, and good examples), an expository can definitely get 10. If you're concerned about boring the assessor, then focus on ways to make an expository more interesting, like:
- more interesting/varied (but NOT pretentious) vocab
- more interesting or unusual examples, i.e. don't talk about Hitler
- deeper discussion of the topic rather than shallow surface-level stuff
- creative twists, for instance, a creative intro that starts with a monologue of a character or describing a historical example in an interesting way
More in
this post (sorry it's unreadable, but dot points recently broke on this site).