The interest generated by the $300K mortgage is tax-deductible as per CRA Income Tax Act S. 20(1)(c), this in turns converts property "Q" into a tax-deductible asset. 

Building #1 is a commercial building converted to a 3000 sqft 2 bed/2 bath residential property.

For example, try to find a SFH for you and the family that has a garage studio, converted garage, or studio in the backyard with a separate entrance.

Looking at a large single family that I am going to convert to a duplex in addition this being a total rehab.

If it does, you may want to look at selling instead of converting to a rental. 

You might consider HELOC for quick & easy, then convert to a conventional 30-year fixed and wrap the HELOC up afterwards if that new payment would make sense for you. 

I recently converted my garage into a studio apt and all the appliances that i have  (Fridge, stove, microwave ) were bought used.

Further renovation will be negotiated if we find a tenant interested said portion as an art studio (option to convert to live/work mixed use space) to pay the land contract for the next 2yrs. 3-5yr plan: potentially keep previously mentioned small portion as a rental for income/ reno budget.

I use a Holding Receipt and Agreement that states we are holding the dwelling exclusively for them until a certain date and it will convert to security deposit funds when they sign the lease and move-in but will be forfeited if they don't.I don't like the word deposit, like holding deposit, because deposit can mean refundable. 

I will be helping a friend convert his Evolve property in SD to this setup soon and decided to setup a document on how to do it.