Check your program's placement list: while it's uncommon for students to go into PhD programs below your range, it's extremely uncommon (zero in last 3 years) to get into the better half of your range (namely the top 10 US programs). There are also many industry placements; some of this reflects personal choice, but keep in mind it's generally the top quarter of Toronto's MA students (in terms of academic performance) that end up getting offers at PhD programs.
In other words, if you're certain you want to go into PhD programs but are uncertain about your ability to be in the top 5-10% of your cohort, I think you should envision a lower range, like #11-#30 US programs and top 6-7 Canadian PhDs. After 1 semester your professors will be able to give you a clearer idea of your position within your cohort, and you can adjust your range accordingly. (Your previous background doesn't seem that strong, so you'll have to rely on MA performance.)
GRE seems fine to me. Only retake if you invested minimal preparation for the first time.