I've never done lending on a primary residence, and I understand the usury laws and such are much different.

I don't think you would need to worry about sub leasing if you're leasing the residence to tenants especially family. 

Quote from @Tyler Stephenson: Investment Info:Single-family residence private money loan investment.

@Eric Fernwood, and @Michael Clardy,  Yes, it is perfectly fine to convert a property from investment into your primary residence. 

I own two long-term rental properties (1 duplex and 1 single family) and also own a primary residence that I live in.

If you aren't a Canadian citizen or permanent resident, I'd also look up federal government regulations as there are newer restrictions on non-Canadians getting mortgages in the last couple of years.

don't buy a random property.

It may be petty for the tenants to hassle you if they know the property is for sale, but a courtesy that I employ when selling an occupied property is to inform residents that while we'll try to conduct all showings (exterior and interior) on set days during a certain time window - sometimes person's may stop by and walk the property without my advance knowledge.

However my guess is a residential loan as your primary residence won't be enough to cover the entire purchase.

Could you elaborate what a resident benefit is or 2nd nature?