Bring this money to closing, the closing agent pays the seller their $43k, and then I get a portion of the $22k in funds to access to begin the renovations.

Most cities zone the same way, think of this as a circle moving inward starting at the outside: industrial, commercial, retail, commercial multifamily (huge complexes), residential multifamily (4,3,2 units), single family residential neighborhoods.

The unit is currently zoned under multifamily-residential (2-4 units) and the City is planning re-zone the parcel into Commercial Office in 2019 (Up to 3 Commercial Offices).

There's commercial construction wherever you go and typically my cheap properties cost nearly $200k to get into. 

I would definitely never give them access to the property before receiving full payment.

My agent gets to make money and I/referrals get better access to more and more inventory.

What are the best resources to use while learning about commercial real estate investing (specifically large multi-family)?

But if you go to an owner you must find a way to provide value to make your proposal more attractive then someone's else.Know that anything over 4 units = commercial... different rules and different buyers.

What type of investing are you looking to do, buy and hold, flips, Commercial, or some kind of combo?

You may be able to get a commercial apartment loan with 20% down closer to 5%.