I was originally told I would have tenants in place before closing and I missed my commercial loan was partially based on this. 

Pretty solid points here, I would also like to add refinancing with a non-traditional DSCR based loan can assist with getting access to cash quickly as there are many lenders that have a lower seasoning requirement. 

His lease says they have use of the entire property for $X, if he wants to increase the rent that is separate from changing what they have access to.

For my commercial properties, I refinance every five years, allowing me to continuously access the equity as long as the cash flow can support the debt service requirements.

A local real estate agent with MLS access and market knowledge will be able to provide the most accurate rent estimate.

While Reonomy is not comparable as it's for commercial properties, Propstream is. 

If the search is correct you keep adding 3 months back and 1/2 mile out until you have them.The best value analyzer in my opinion is only accessible by realtors.

Get your RE license and sell these on marketYou can also use the marketing skills you learn and direct it toward apartments or commercial real estate and jump into that asset class.

This information is public record, and anyone can access it.

And that residential department will often not speak to the commercial department.