I see that a lot of luxury apartments are either approved or already under construction and I'm a little skeptical on how that will impact the demand for rent in the area. 

I would imagine that mostly impacts things if adding a DADU or changing the exterior of the property.That said,   if the home is currently built-as single family you would still need to pull all the permits, and go through all the rigomoral (sp?)

House hacking is definitely one of the best first steps you can take and will probably have the largest immediate impact on your financial situation.

I am in the process of taking on a new job and as it is a 1099 contractor position (selling insurance) and I am unsure of how this might impact my ability to apply for a loan and/or be granted one for a mortgage.

Has construction and real estate been impacted much in TN by the shutdown?

I would require some sort of proof that they have lost income due to COVID-19 that impacts their ability to pay. 

If a tenant pays late or defers due to the virus, that doesn't negatively impact their credit.

That will have a big impact on the cost of rehab. 

I once heard something that I thought was really profound.

You'll find that different areas, property types, condition of property, target market tenants, etc. all impact what the actual numbers will be.You may want to explore and understand the 1% Rule and pick your number.