Schulich is definitely a good B School and it is a wise decision to apply there. Your concerns regarding low GPA can certainly be offset by a good GMAT score. It is an edge by having some continuing education credits along with your work experience, as it shows your inclination and strive towards further education and will be advantageous in your application.
Apart from your certifications, the other things in your application that you need to work on are Essays and GMAT Score (average GMAT Score of Schulich for MBA being 660). This is where you can demonstrate your leadership qualities, achievements, professional vision and other abilities. A well presented and perfectly written essay is critical to make a strong case for yourself during the final interview.
It is highly advisable to seek assistance from professional consultants for guidance to get a good GMAT score and also get your Essays evaluated from them before sending it along with your application. Also consider taking classes for GMAT preparation to have an eligible GMAT score.
You can visit http://www.general-ed.com/general-mba-essay-analysis
to learn more about professional essay evaluation services and http://www.general-ed.com/Online-GMAT-Preparation
to see about online GMAT classes.
Feel free to post any other query or concern that you might have.