2. Of course you shouldn't count foreign students or temporary workers, they get counted if they choose to stay. If you were counting them, as well as immigrants, you'd be double-counting the same people.
3. I didn't realize that the singular suburb of Vancouver called Richmond, BC (Population: 216,000) can be referred to as 'several cities'.
4. Why does a young[1], educated[2] person moving into the country in the prime of their life 'put an enormous strain on everything'? Would you care to elaborate? To me, it seems like a gift of all the costs of early-life childcare, plus the cost of a K-12-post-secondary education from their country of origin.
[1] https://www.statista.com/statistics/443305/international-mig...
[2] https://www.statista.com/statistics/555224/number-of-landed-...