materiality calculations

I think that is just my advice how you can clearly earn the credit - it is just a convention for answers generally (not just AAA) too show where a % comes from. Since this is not an exam where "all workings must be shown" you would get credit for a % of a specified benchmark being correct without the working.

But BOTH may well me relevant e.g. if there is a risk that impairment may not be recognised the other side of the debit P/L is credit PPE. THIS is not a matter of judgment. The judgment is if, for example, if % PBT is > 5% but less than 1% total assets. But to reassure you - all relevant materiality calculations will be credited subject to the "cap" on marks - and there is not negative marking - so marks won't be deducted for unsuitable calculations (they just won't be credited!)

Before you audit there is the possibility "risk" of misstatement - by the time the auditor has obtained sufficient audit evidence, he should know whether or not there is material misstatement. I don't know why you are writing about immaterial misstatements - if you meant material, then do take care in the exam to write what you mean.