To cut to the meat of your story:1.

I know it's talked about all the time, but I recommend people leave their equity and focus on increasing income, cutting expenses, and saving for the next investment.

I don’t do a lot of deals but when I do I do it very uniquely and cut out anyone that’s trying to make a profit but me.

The pennies saved today are at cost of the dollars tomorrow when cutting out "boots on" professional management. 

Go to meetups, tell your story, and I bet you'll find experienced investors that will help you out (by giving you advice, not by cutting you a check or partnering). 

If the property owner is a "long time childhood friend", then she may be willing to cut you a deal where she pays for the closing costs and/or she may contribute to any repair/remodeling work that the property may need.Once you move in you could house hack and start saving money so that you can acquire more properties. 

And to Mike's point, if money can be made, why not do it yourself and self-manage the STR or even hire a professional manager and cut out the middle man arbitrager.

Should I start an llc/property management or just take my cut off the monthly net?

This fuels the demand for multifamily housing.Concentrating investments in one market allows you to scale faster, reduce costs, build relationships with brokers and acquire off-market deals. 

I’ve thought about a million different models but the truth is even if they make sense in theory I’ve come to the conclusion they may be too convoluted to explain, so I will try to keep getting 2.5-3% and if I have to cut commission to gets deals done I’ll do that as well, but I think paying some percentage to sell a home is probably here to stay just possibly at a lower sometimes.