As already mentioned it definitely depends the specific scenario! 

Specifically:- Are there any exceptions or tax treaties that could eliminate or reduce my US tax burden on foreign rental income that is otherwise taxed locally?

I thought that since I already own 2 properties, I should focus my 3rd in a very specific area where I could build out a soundproof music studio/pianobike storage in a garage in the back and rent out the house.

In order to do this you need to know what's going on in the area of your rentals, consider your exclusive contractor relationships, and get someone to run a viable cost estimation on your property (specifically an "insurance" cost estimation). 

I'm feeling apprehensive about making a mistake and not sure where to start and really want to get specific on my strategy. 

Registre Foncier du Québec This will tell you about anything that has happened to a property Sale, Transmission, Lean, 60 day notice, Expropriation, sub dividing land....Very had to find specific deals in here, you’d need to be lucky to find a 60 day notice, you have to search every address and fall upon it2.

Feel free to ask any specific questions.

What was the outcome?

@Sara Habtom Your question is lender specific meaning you need contact and start asking these questions with a local lender.

I would always have a modern outlet co-located to bedroom windows specifically for that reason. 5.