In my analysis, I estimated the annual insurance premium as if they were combined, then I learned that the 1 bed 1 bath must be insured separately.

If it is, why can't you buy similar properties that you are renting with the money you make.If you get $200,000 annually(split proceeds with the other owner), you should be able to buy almost any type of property.

I do not believe they were founded by Jeff Bezos he invested from reports. also In same reportSingle-family properties paid an average annualized dividend of 3.7%,but check sec filings 

Unit turns run $3K–$4K each, so with her markup my all-in annual PM cost is ~$112K (≈18–19% of gross).

Going the LLC route can mean higher interest, bigger down payments, and extra costs for setup, annual filings, and accounting.

In particular, I'd like to know which has performed better for you personally in terms of annual cashflow, and which you would recommend to a beginning investor?

Annual is now more like $50K.  

And in my very seasonal market, I need the annual PITI to be equal to or below the gross booking revenue for my 2 busiest months (July and August). 

I've also had under contract deals derailed because of weird things like tenants with free roaming birds tenants were hiding, and most commonly people flat out hide numbers or lie about rental income and annual expenses.

Request the landlord policy endorsement quotes in writing now before closing, as this could add another $500-1,000 annually and dramatically affect your numbers.