Hey there,
It's hard to say for sure what scores would be needed as they change each year, and also differ between cohorts. But here's just my experience:
I received a raw 35 in 2017 — it felt difficult when I was doing it, but now in hindsight, I really didn't put in any effort (I didn't start my oral scripts until September, and did no practice exams). So I'd say it's not too difficult, and this is coming from a white guy with zero Chinese background forced into SLA against his will.
Regarding scores, my GAs were A / A / A, and my exam scores were:
.
• Oral: 97/100
• Written: 237/300
• Total: 334/400 (A)
.
IIRC, my (unmoderated) SAC scores were probably all around 50~60%.
You should probably be aiming for an A at the very least on the exam to secure a 35 raw. In 2017, the A range was from 321 to 336 (out of 400).
Hope that answers your question.