No worries! I’ll try to clarify them.
Question 9: On this unit, there’s a separate control board called the heater PCB. And on that PCB, there’s a relay for the heater (this is all information you can find in the tech sheet provided).
The question wants to know what leg that PCB is switching to the heater. Is it line? Is it neutral? Is it neither?
Question 10: This question is asking how many different voltage supplies the main PCB is sending to the sub PCB, and what those voltage supplies are. You should be able to find the answer to this question by looking through the schematic carefully.
If anything is still not clear, let me know.