I'd have to agree with Sam, house hacking is great, but also starting out with a rental that you'd live in is ideal.

So I have an opportunity to convert an existing large addition(15 x18) at the back of home (away from current bedrooms) into a master suite with full bath (making it a 4/2 with an office). 

I Have a bungalow with a legal basement suite in Avenmore and I need to replace my manager.

ADU's or Mother-in-Law suites offer so much flexibility.

Multi units prefer 2+ bedroom units, 1,000+ square feet each unit, side by side is ideal if possible, want at least electric and gas separate, any area can work for these as long as it isn't a D area, but usually B-C class works best since buying these primarily for cash flow.

Ideally, I'd like to replace the whole thing, but there are alot of issues with the placement of the heating and condenser units and whether there is enough ventilation.

Also, when is it ideal to be issued?

I think ideally we are seeking tenants that are a part of the college town workforce as you mentioned. 

These are often ideal for long-distance investors, who what to work with an established team that manages all aspects of your investment. 

There are so many fantastic resources available today for RE investing but I would first recommending defining your goals and then determine which RE asset class can best suit your goals.