While the returns can be much greater, the cheese moves much faster in the game of short-term rentals, and the knowledge and strategy required when it comes to existing and future government regulation (on the city, county, and even state levels) is hugely important as one could get put out of business at any time.

That will allow you to build up a network of contractors and suppliers that will enable to to address problems faster and more cost effectively.I would also recommend buying a home warranty program if you are planning to hold the property and make upgrades over time. 

You'll get there faster and easier than becoming an agent just to learn how to invest.  

I'm determined to get out of the rat race ASAP and with one multifamily I think I can achieve that (much much faster than SFRs at the very least).

That experience alone will take you further, faster than any other thing. 

The slope of the land and how much dirt to be moved also comes into play as it can get expensive to level for site work.Additionally inventory levels of similar locations with vacant buildings where developers or tenants can go in cheaper and faster might be competition unless you have one of the best locations in the area.Basically what I am saying is that there is a lot to this and you need a specialist to help if you are trying to extract any additional value out of the property versus it's current use.

Using amortization calculators I noticed I could pay off the loan a lot faster by adding extra payments.

It took me about 1 hour and I was done . now I have lots of time to get a replacement the spare covers the current  problem .I dont repair refrigerators , washing machines or dryers , its cheaper and faster just to replace .

Jason,As an accredited investor you could definitely do purchase least options but at the same time acquire some sandwich lease options to see your portfolio grow even faster. 

It's almost always cheaper, faster and a whole lot easier to deal with the Owner rather than a  bank.