I had a tenant who had a Surety bond with Assurant for the security deposit, but they are getting out of the business and are not renewing any of their policies. 

Simply put, more buyers for the bonds = lower rates.

Interest rate rates follow more of the 10 year treasury in the bond market.

The NOI hasn't been the most attractive over the last 2-3 years.

It's never the last helicopter out of Saigon.

I’ve actually seen out-of-state BRRRRs work well over the last couple years, but only for investors who treat it like a business, not a side project.The key has been building a local operations system (property manager, contractor, and boots-on-the-ground contact) before ever closing.

What you'll see though is the bond markets (which control mortgage rates) are influenced heavily by inflation expectations. 

Nothing much has changed in that arena in the last 25 years that I've been at this.

That’s normal in appreciating/coastal markets.Paying off the mortgage is basically buying a bond at 4.375%.When you pay off $265K at 4.375%, you’re getting a guaranteed return equal to the interest you’re no longer paying, plus the cashflow jump you mentioned.

I am concerned if tenant vacates (who is original tenant for last 6 years ever since i bought this property hoping she will extend lease which is coming up in 4 months from now) it will be bit hard to take care of mortgage for many months from money from my pocket.