Repairing water damage and fixing broken items is the bear minimum for a landlord.

If you have class C rentals, I like to use Traffic master Grip Strip Water Resistant Luxury Vinyl Plank Flooring.

This means, no electricity and no water as the well can't pump - which also translates to you get one more flush on each toilet and then you are done.  

They know the tenant base, median rents of different areas, how much to increase rent each year, ranges of repair costs (ex: tenant calls and says AC isn't working, no hot water, faucet is leaking, the HVAC system goes out).

To manage this, find the average electricity, water, and gas usage in your area.

Maybe find out you didn't replace cathodes, and the water is harder there.

You should be calculating Cap Ex for all long term items that will need replacement at some point - appliances, roofs, ac, water heater, etc.

Hvac, Insinkerator, furnace, water heater, toilet, fiberglass tub, roof, driveway, etc...Here's a link: https://www.hud.gov/sites/documents/EUL_FOR_CNA_E_TOOL.PDF You might also want to consider a home inspection for each unit with a written report, and a sewer cam report.Good Luck!

Yes for houses directly on the water (such as the bay) and in a flood-zone.

Currently, there's only one water meter for the entire duplex, and historically, I've been responsible for paying the water bills every month.However, I believe it's time to transition to a system where the water bill is split between the two tenants.