the HSC is not that easy ... you can't rely on your 'general' knowledge to get through. You need to be able to write specific text types to get the top marks. Only 29 people in NSW got Band 6 in 06. Not that easy hey>
IT VET has no assessment mark. It is also OPTIONAL and the school is not obliged to enter you, so don't go cruiZin the subject. The trial mark is used should you not sit the final exam. To get a Band 6 you need to take half yearly, yearly and trials seriously. You need the feedback - don't leave...