I am a physician from Peru, currently living in Ontario with a PR. I worked at a very well known clinic in Peru who is accredited by Accreditation Canada (which means it has passed Canadian standards). My English is excellent as I lived in Florida for 12 years from age 10-22. I can tell you that from experience, it is extremely difficult to get into jobs like medical liaison or research. For medical liaison, most ask for a license to practice in Canada, at least 5 years of experience and/or research experience. As for a job in research itself it is hard to land as like someone else mentioned, there are lots of people with Masters and PhD graduating and have experience in the field so they are usually the first ones to be considered.
I applied to A LOT of jobs when I arrived here, and was turned down by most of them. I landed a job as a medical assistant, which pays very little but that gave me the Canadian work experience I needed that later on landed me a job in the CRC and TOH as a research assistant (though the latter was also by a friend of mine who is an IMG and an IM resident there). So it's far from easy for us IMG physicians here, regardless of what path you want to take within the field, and I try to make that clear to anyone that asks me for advice on this topic.
I am currently working on getting my license here, which is also a hard and expensive road. But that's a different story and the CARMS stats speak for themselves...