Calculation of Gross Rental Yield, known as gross in the industry, is simply calculated by the rent and property price as shown below and is used to easily determine the profitability of a property.

Suddenly they had found themselves without tenants in multiple properties because many of their tenants worked in a lot of the same industries that people got layed off in, and found themselves having to deeply discount the price of rent just to get a tenant, but in doing so, were still bleeding.  

I see former players from the 2000's coming back to the industry under different business names, and some of their prior work was less than stellar.

"Commercial" could mean a lot of things: industrial, retail or office, typically.  

The problem is you're combining a valid investing metric (loan pay down) with a bad investment (paying market value, limited appreciation prospects) and a cash-flow need (quitting the w-2).First, we never pay retail. 

If it were a product that had a price point available to non-institutional, retail investors or small businesses it could be interesting.

Most brokerages will have a retail investment sales team and likely a retail leasing team.  

As I said these "number of days" can change and float as needed but in my world its not only reasonable but common and customary for TT's to have free rent during buildout.for reference we are traditionally doing $500K - $800K build-outs in grocery anchored retail centers. 

mixed use residential conversion of retail space to str units plus real estate office, two restaurants space tenants What made you interested in investing in this type of deal?

Unfortunately, safety in STR is becoming a major problem, that the hotel industry is capitalizing on.