In my view, the introduction should begin with a sentence outlining your contention, a direct response to the prompt (well, i like to anyway). The examiner will have a fair idea of your grade after reading your intro.
Being linguistically powerful does convey confidence and control of language, but as goose mentioned, it must be only employed if you clearly know the meaning of the word. "Didactic" was a very popular word in my class due to its appropriate usage for Dicken's writing style, yet few were actually aware of its specific meaning.
I personally advocate a thoughtful introduction, one which establishes a clear line of arguement, and references the various factors/characters and writing devices that support YOUR contention, and not that of the prompt. A common mistake is to deviate from your line of arguement, affecting your ability to maintain the tight control of discussion needed to earn high marks.
English is a active learning experience, and you must experiment with your style early in the year. I personally wrote no responses in the two weeks leading up to the exam, bar one practice exam that the school ran, as very little improvement can be made at that stage of the year. Your teacher does not possess all the solutions to your problems, and finding other sources of criticism is imperative to broadening your own perception of your skills in this subject.
Furthermore there are very few iron-clad rules of essay writing, structure is of course important, but by no means is TEEL the only option available to you. If someone is trying to tell you that you must quote in your conclusion, or that you must not, then they are wrong. I certainly have my own perceptions of appropriate essay writing that i reccomend to others, but do not be limited by the rules of others, you must experiment to find a style that suits you
If you are not confident with english, then you post here at your own risk, if you post work and receive negative (but almost always constructive) criticism, you may find the standard of your school does not correlate to the rest of the state. Too often i have seen students suprised by mine or others assessment of their work, of which they thought was of outstanding quality, only to find it was mediocre at best. However, FSN is a positive environment for the most part, and i've yet to see the spiteful and mean spirited comments of people's work that i've seen on BOS. Be aware that there is always someone, somewhere who needs to bring you down to feel better about themselvs. This is the nature of the VCE beast, and english is not the only subject i which you will encounter this attitude.
My only rule of english is that you must practice. I assisted students this year who struggled with aspects of the course, only to find they had only written one or two pieces in the format they were struggling with. You are against students who will write in excess of 50-70 essays for the entire year, you simply must practice. If you take anything in from my lengthy diatribe, then it is that you must practice.
PRACTICE.