From your further details, I would suggest SkyTeam is the alliance for you if those flights home will continue to be on Royal Air Morocco since that's the alliance it is a member of. That would include AF/KLM which could also be an option since these two carriers have been offering very low fares to Africa on a regular basis. And if you do fly into the US at some point, DL would be the airline to take so you can earn mileage on those flights.'

It doesn't appear that you will be doing much, if any, domestic flights within Canada so this doesn't really become a factor -- other than perhaps getting to YUL for your overseas flight.

The issue becomes which airline's FF program to sign up for, since you can choose from several SkyTeam members. I'm not familiar with those programs, so suggest you might pursue your query in the SkyTeam forum.