Hey MSW_CU,
I am actually a Carleton (2 year) MSW student currently. I just checked my e-mail and I was accepted to Carleton on February 15th (my first contact/indication of acceptance was from Sue Brady - so look out for that name in your e-mail).
I'm not sure what they are looking for or how they make their decisions - I can only offer a little bit about my experience.
I had about 4-5 years of volunteering (3 different organizations), 2 years working full time as an addictions counsellor, I had an A- avg. in my last 2 years at University, and had completed an additional college program in addiction.
I know that my cohort has a very wide range of interests/experience, which is why I can't offer more in terms of what they are looking for.
I think if nothing else, the fact that you addressed the structural social work approach in your application will definitely help!
If you have any other questions, please feel free to let me know,