I'm first gen, didn't have to resolve customs issues but I do represent my family to resolve different issues. What you have done I think, shows responsibility, cross-cultural communication skills, and the ability to understand regulations. I'm not familiar with Dal or their criteria but for most Canadian med schools, what they look for are certain attributes as opposed to knowing what pt care/being a doctor is like. When it comes to challenges w/in your community, you can also discuss how there are others who face similar challenges as you and use your own experience of overcoming challenges