Too Conservative Replacement Reserve?

[Monika B.]

I bough my first rental (duplex, non-owner occupied) 2 years ago and would appreciate feedback on my replacement reserve amount, and thoughts on needing flood insurance in a non-flood plane.

Monthly income is $1,995, PITI is $1,253, water/sewer is $110, and repair/maintenance set is apprx. $30/month. I had approximated the remaining useful life of each major house system and the approximated next replacement date and backed into a $423/month reserve for both units ($211/unit). That is over $5k set aside annually on a $240k home (purchased for $215k). The amount I estimated is over $3k higher than the national average of $900/door. I had needed to replace the furnace and some electrical, and updated the bathrooms before renting it. How are other people calculating this? Including my approximated reserves, I'm still managing a 1.13x DSC. The top-down duplex is 100 years old, rented at market rate, near a college and military base, and has been 100% occupied over the past 2 years. I'm looking to buy my next property, and would appreciate the feedback for my next model.

Part 2: I don't have flood insurance on the property. The property is not located in a flood plane, however this is  a hurricane-prone area at sea level and I believe the risk is higher than the flood map indicates. The building has a brick foundation. Would you go without flood insurance, and risk self-insuring in case of hurricane. I think in a minor hurricane (category 1-3), this would result in $20M in damage max. A large hurricane (4+) would cause almost a total loss. How do other investors deal with this issue? Do other investors diversify the location of rentals to deal with area specific issues, or is that a risk that's usually assumed by the investor with hope for the best?