I currently own and self-manage two STRs in Maine and should be closing on a small 'cabin campground' with 10 cabins nearby that will also be operated as STRs. 

My main goal is it be able to retire at age 40 from my main job and work entirely on my real estate portfolio.

Main thing to watch out is DSCR Ratio.

Although as @Drew Sygit asks, what have those PMs that pledged to do it better now learned that may bring them back into line with main stream service providers? 

For me, it was live in flips, short term rentals, mid term rentals, good income with a solid savings rate, buying after tax index funds, paying off the primary house, driving old cars, moving a lower cost of living area (from Houston to small town Maine), and selling a business to push me over the top. 

Generally local agents have one purpose, to sell.

A couple thoughts on your question:I tell our STR investors in Colorado that their main goal should be to set up the right way right out of the gate.

I'd like to add another SFH to the business  in the near future with the main goal being grow the business as fast as possible. 

Now my main issue is I need a fire detection system in a enclosed back porch that leads up to all three floors, but I don't know what's the minimum I would need to be compliant or that the fire marshall is suggesting what he wants or recommends.

What’s your main focus, or what are you hoping to get out of your journey here?