The answer to a question might be at any point of the recording irregardles to when other answers are played.

The answers to questions always come in the order of questions on the exam paper.

Some passages in the recording might not contain answers to the questions at all.

This is actually the case. Such passages might be used to help to figure out how current position in the recording corresponds to the position in the sequence of questions.

A special "signpost" language must be used at all times before questions blocks.

Signpost language is indeed often used in the recording and test takers may use this fact to their advantage, but its use in not mandated.

The recording must contain exact question wording immediatly before the answer is given.

This is not neccessary, in fact relevant phrases are often paraphrased.