You aren't required to write in the comments to complete the course. At the bottom of each section there's a button to mark each section as complete, as long as you do that for every page it appears then it's all good! The final test is really easy, I just did it yesterday. There's no time limit and you can refer to other sections of the course as you are doing it, it's pretty much just like an open book test. It's out of 60 marks with 3 marks per question, and you have three attempts for each one (but for every wrong attempt is a missed mark). Just make sure you read each question and answer carefully, but it's mostly all just common sense really.