The big deals will be vacancy, capex and appliances. (3 water heaters, stoves, fridges, microwaves?

You may have water traveling down the bedroom wall, then across the dining room ceiling to the lowest spot which happens to be there.

Unfortunately, you said some magic words that chum's the waters so que the "please contact me PLEASE CONTACT ME" replies vs actually answering to what you posted...... 

Year 2 had some large expenses, including some CapEx items (water heater, roof).

PRELIM LAND PLANNING- do a preliminary layout, please remember stream buffers, specimen trees, ANY jurisdictional waters (its a good idea to have you county water systems guy come walk your property with you to verify any jurisdictional water systems and what the required state and county buffers are for those systems).

I have had a home destroyed by fire; never by water.

IE at the time if you built on all the hundreds of thousands of lots there you would have perpetual grid lock not to mention water quality etc etc.

My extensive real estate experience consists of 1 flip.I have an idea and I'd like to test the waters here in the forums.

Inherited tenants are usually a negative, however in that area leaving the duplex totally vacant makes it a target for thieves to come in and steal your pipes, furnace, and hot water tanks.

Each unit is individually metered for power and water.