Yes USMLE has nothing to do with QE1 or any Canadian exam for that matter. Anyone with a permanent resident status or visa can take it...but the first step is Evaluation Exam. Evaluation is an all mcqs exam, while QE1 has 2 parts...the morning session has 7 blocks of mcq's...the evening session is a bit trickier...it's called CDM (clinical decison making) part...you are either given lots of options to choose from or you may be asked to write the management/answer in the space provided.
I absolutely agree with doctorF ... Canadian system is not at all img friendly ...too difficult to land a residency here. It's a quota system here...IMGs and CMGs apply to different streams...they have limited IMG seats ...and many of those too are left unfilled every year...not because there aren't enough applicants...but only because they choose to refuse hundreds of applicants.