Since you'll be doing some research to compile a list of people to call, this could be an extra layer of long-term team & relationship building, if you will be hiring professional property management for your portfolio.I chose this model when I was seeking these members for my team and have loved the trustworthy relationships that have been built from it.

I liked it because it had a nice cushion layer on the bottom, was thick, and flexible.

I think their protection comes from the low appraised value (which was my experience) With that, they build in a layer of equity to protect themselves. 

but on top of the actual snack, you pay 30-40% additional layer of cost (cleanliness,parking ,reviews,feels of luxury and so on).

I'll do a 2 layer setup with the room side layer to be cute & window side layer blackout.  

And maybe that "small guy" painter will turn out to be a great guy who will refer you to a "small guy" tile layer?

If you have capital, then SEO and ads can be vital forms of passive outreach/marketing.

National banks have so many layers of corporate policy they rarely do anything outside of the box.

It also sounds like you have mortgages on these properties so that is one layer of protection.Normal insurance, another layer of protection.You could add an umbrella policy for a third layer.Once you start paying off properties then you could start moving these to an LLC.Take care of your properties and your tenants and it will be unlikely you get into any trouble.I would be less inclined to BRRR if you have good interest rates on your current rentals. 

The LLC will be your best option (with a new bank account) as there is only one layer of taxation on the profits.