My current income is sufficient enough to cover my living expenses, live comfortably, and put a portion toward savings each month.

Taking your screening method above- as an investor, it would make sense that you are choosing the applicant with the best balance of income, credit, references and a clean background. 

Foreigner investors can either pay a flat tax of 30% of their gross rental income or elect to file an annual US tax return and reduce their taxes by claiming deductions relating to ownership and managing the property.

This has caused our clients a lot of missed opportunities or having to grapple with putting 15% down on a duplex and 25% down on a 3-4units.This new program changes the game, now clients with income $92,000 can put 5% down up to a 4 unit. 

I have been looking into other sources of income and thought of getting my mortgage brokers license.I am well connected in my market and am still relatively young at 24 with lots of friends and peers that will be looking to purchase their first homes soon.

There will be no capital gain due so no exclusion.If you really want to capture the section 121 exclusion while keeping control of the property you can sell it to an S Corp, but then you won’t get all the real estate tax benefit of passive income.

I have about 1 week left on my initial 45 day period to put properties under contract to avoid the tax implications from my sale of the commercial real estate. 

What is the best way to approach this from a property tax standpoint?

Goal is to reduce your biggest expense (housing) with income coming from the ADU to save money for your next RE purchase.

Then renovating my historic building and sell my historic tax credits.