PMs and realtors want to use people they know that have been in the business and do a good job for them.

Or should I grab plans from a local builder and work with their architect to modify the plans to more of my style?

I use my license for multiple activities: Of course- comps, when buying and when selling, tax data- to see what I am about to pay when i own the home ( for long term holdings), check the DOM (days on the market) for the subdivision I am either buying on, or when I plan on selling, etc. 

,  occupancy rates, capex plans, competitor rental rate study, market study, etc.  

Their plan is to raise rents (on the poor remaining souls, improve infrastructure and exert some sweat equity. 

Looking to ramp up my business by advertising, specifically on Facebook to start.

You can withdraw from your 401k starting in the year you turn 55 if you qualify.I am following a plan similar to yours.

But know the business. 

My business partner and I have a monthly fix/flip forum we hold in Scottsdale and mainly just work with flippers/investors. 

The STR model is a different model and where it is at in it's business cycle, the average STR owner is not doing well.