IIRC, that is much better than mine were, and I got superiors for it, so you should have no problem. I can probably dig up some good ones of mine if needed but you really seem to be on track. I've helped a few people I know get into MHS and McROb, and what you seem have on top of other students is:
a) You can actually write in the time frame. Most people can't. Try and get writing and planning to about 12 minutes, with 3 to check over though. You have plenty of time for that.
b) You have a very clear structure and contention. This is good.
c) Your vocabulary seems to be much better than the average kid your age.
The only criticism I have is your signposting in the intro uses 'in this essay...' however for the exam its probably OK, and if you were told to do it that way stick with it.
Make sure you are decent at maths and the creative writing component. However I didn't even finish one of the math exams so its not the end of the world. Timing is the big thing.