If you add 2 ADUs traditional conventional F/F is typically not available but in this case the 2 units makes 5 unit.  5 unit s commercial MF with different rules and means to value.

I did it for almost 5 years with minimal issues back in 2010's.

Depending on the dimensions of your tract, your goal should be to orient your garages with the elevation difference going front-back or back-front. 

Far more profitable than SFR s given the capital required and time to flip them.. 

There's a very good chance the issue(s) you face have already been discussed and answered.Ask questions in the appropriate forum.

I think your strategy by just trying to ask respectably is the best way to go here and then you can elevate things if necessary if they're continuing to disregard the non-smoking clause.

Properties are so much more expensive it seems like a whole different world than a lot of real-estate investors likely started in and it leaves me wondering if real-estate will still be a strong investment for my generation or really just me when I am in my 20's.

Low 9's is not bad for a no ratio DSCR loan for a foreign investor.   

Key to your approach, as you seem to already understand, is that it requires elevated levels of planning and due diligence, but with this approach, it can be a profitable strategy.As you are in the process of narrowing down locations, start engaging with local experts to best understand market dynamics and compliance requirements with local laws.  

BiggerPockets has lease agreements here: https://store.biggerpockets.com/products/landlord-forms-by-s...You can also use sites like Rocket Lawyer to help you: https://www.rocketlawyer.com/ If you speak with a lawyer on their site, it may a little more affordable.I hope this helps.