Canadian and U.S. programs are different. I have no experience in Canadian graduate programs so I cannot address their perceived value to admissions committees and I do not know whether they typically are funded or not.
I agree that personal statements and writing samples ought to deserve higher consideration than GRE scores. Let me be clear: jferreir is right; you couldn't take an overall poor application and improve it by raising GRE scores alone. But a top GRE score will get your application read. It is the first step to getting anyone on the admissions committee to pay attention. Writing samples and personal statements are important - sure - but if the GRE isn't high enough, a committee member, who may have liked what you wrote, will have difficulty convincing his/her colleagues to admit you.
If you have a high GRE and still have difficulties. It may have something to do with pedigree - where you went to school and who wrote you letters of recommendation. Getting an M.A. is one way to possibly improve that pedigree. But in the states, if you want to improve your pedigree that means attending a bigger name program where the M.A. is less likely to receive funding. If you can just write a check and go without debt, by all means go. Few people I expect can do that. If attending an unfunded M.A. program means large quantities of debt, then you have to seriously consider how much you're willing to pay for those letters of recommendation.
jferreir is right that a polished writing sample and a well-researched personal statement showing "fit" in a program will go a very long way to improving your chances of admittance. However, my advice about avoiding unfunded, American M.A. programs centers on just why you believe you need to complete an M.A. If it's to improve pedigree, fine - but it's going to cost you, and you may have difficulty getting professors to pay attention.
I think it a bit optimistic to imagine securing any publications as an M.A student let alone a few, but it's certainly been done. I, however, would be careful about what and where you want to publish while you're in this maturation process. But that's something else entirely.