I've never heard of anyone needing a rental license before unless they were operating as a short-term rental on a platform like AirBnb or VRBO and their city/county requires them to be licensed for vacation rentals.For a traditional rental I'm not aware of nor do I see any reason why it would be an issue. 

I look forward to seeing you grow as an investor and on this platform.

What other platforms should I use to market the property?

Many of these coins have no utility on their platform even, which is similar to what you have said. 

I wanted to know what is the most efficient way to list my properties over multiple platforms AirBNB, VRBO, etc., and have them synced to one calendar.

The original stairs were a narrow very steep nightmare.On a recent foreclosure/flip we had to tear out the (3) 4ft long cement platform steps (circa 1950) leading up to the small patio at the front door as the rise was deemed too high.

Referral Platforms.

I am slowly learning a lot about posting and using this platform to further my education.

Put a little money into to update & furnish it but does extremely well because of one of the rental platforms our company is on.

I wanted to gain some information as to what techniques to use, what houses to look for, what platforms to find cash investors and where to find local houses without using the drive for dollars method.