Well, got it and read through. Good thing about it is- you have really kept it short.
So below are my points that you might want to change..you perhaps should as it would make it appear right.
Greeting-
Error 1: Dear Consular Officer:
Write instead- Dear Consular/Dear Officer (either of those not both!)...and take off that colon too
Error 2: In the very first line, you don't have to necessarily have semicolon. But if you really wanna have it, it should be superseded by a lower case "i" an not Capital. Else you keep a period there.
2nd paragraph--I wouldn't say this as an error... as I am not sure if you really have to tell them about your legal status repetitively. Work on that too as moneywater mentioned.
3rd paragraph- I guess it need not be mentioned at all...
4th paragraph-- Its too much of defaming about your country of origin. You might praise the country you intend to study in but shouldn't cause any disparage to your native. To me, it might not be so favorable as the VO might think you may not go back to Mexico after graduation and rather settle in Canada as you yourself have just written you want to be in a place where the quality is in par with USA. You might have to alter it a bit as well!
6th paragraph- This sentence-- "My gpa reflects that I am a person of high integrity" is not really needed is my opinion. Let the SOP and the words and the truth behind it reveal the integrity. Hope I am not rubbing your intentions as I just wanted to be genuine with it. Well, the VO's can certainly see through it

Don't worry friend.
8th paragraph- not sure what your intended course of study is.. Assuming its either English/French, I am expressing this- explain how and in what ways this study is going to help you in Mexico. Apart from family connections what would make you go back in order to establish yourself in a stream related to your study. Leave some strong points in there. Not to mention about the blank spaces are for... You could take those off or fill it up
Last paragraph- Again reiterating on the factors you considered...allow them to consider rather than you mentioning it. Also re-phrase the character inclined words and mode citizen etc.. otherwise it seems to be good for me
