Ensuring the questions are clear is important as many candidates are from a background where the first language is not English. The sun questions have had a good reputation for clarity. Feedback from people who have taken the old or new version of the exam have not reported significant problems in understanding the meaning of questions. Snippet based questions are harder to memorize and pass on to friends. Any publicly available certification will eventually have some question leak.
Some people attempt to pass the exam by trying to memorize the questions that come up.
This seems to be a faulty approach on many levels. It is probably easier to learn the language properly than it is to memorize enough questions to be sure of passing the exam. I do not know the exact number of questions in the question bank but it is many hundreds. When you sign up for the exam you sign a confidentiality agreement that you will not pass on questions to others. Please respect this agreement.