Doubts

Proof in total. Let's say you were auditing ticket revenue for a cinema. You should be able to get evidence about the number of tickets sold. You will also know seat prices. Therefore: Total revenue = Tickets sold x seat prices. It won't be spot on because some seats might be at a different price to others, but you would expect it to be close to the revenue reported. Assertions. Obviously, it depends on the question (usually no need for detail on assertions when talking about audit opinions). Where it's really important is when you are describing an audit procedure as you should say which assertion you are collecting evidence for. So in the example above on cinema revenue, the proof in total will give evidence about teh accuracy and the completeness of the revenue figure.

Letters and emails to and from the client's lawyers.

What do you mean by review engagements?

A review engagement is where the FS are reviewed but the work falls short of an audit. It is sometimes asked for by companies that are exempt for audits to give members and directors some assurance that the FS etc are OK. The opinion at the end of the engagement will be a limited (negative) opinion ie that nothing was found leading to a conclusion that the FS have not been prepared properly. Review engagements are cheaper than statutory audits where a positive opinion is required.

Usually the question instruction is identify and describe, or idendify and explain. The commonest marking allocation published is 1/2 mark for identification and 1 for description eg why you are doing it. If you just day 'Do a bank reconciliation' withoug explaining why, then that's probably only 1/2.