Many lenders have different requirements but typically if you have a downpayment of 25-30%, closing costs, and 6 months of reserves (6 months of mortgage payments), you'll be qualified.

In addition tenant flips take work and have costs.  

The HELOC/HELOAN will have the lower closing costs and you're not giving up your 3% rate.

A percentage discount off of what it would cost for daily stays on the booking platform.

No the rates are not on par with conventional when you figure in additional costs and pre-payment penalties. 

I have talked to my lawyer and it is going to cost $902 to evict them.

Before being approached to help with the development costs, I had considered on buying after the development was complete; 4 lots then having 4 homes built, selling 2 and keeping the other two to rent out.

I'm wondering if the insurance costs are hiking up the expenses.

This sure keeps turn over costs low and at bay.

Realistically, if rents can't keep up with costs over the longer term, fewer people will buy rentals and there will be fewer options for those who can't afford to or choose not to own a home.