You want to build a team that way when hiccups/problems arise, your not dead in the water.

With this platform landlords and tenants can have access to important documents, have insights on water/electricity and gas usage, have a better connection trough communication tool, have personal popups, and much more features that will be created.

- Does it require extension of public utilities for water & sanitary service to the lots?

You have also account for items such as property taxes, insurance, repairs, maintenance, contract services (landscaping/snow removal), capital expenditures (roof, water heater, etc.).  

We currently pay water, and the residents pay electricity.

Outdoor complete kitchen with water, electrical and drainage 5. 

Your best conventional financing terms will be for a primary SFH, which you could always turn into a pure rental later on.

do new buyers have to sign off on properties not yet brought up to public health standards for Drinking water?

Have ALL of your ors in the water, do/setup marketing in many channels (SMS, post card, PPC), learn how to carve out lists that target motivation that you want. 

Saving for DP and repairs, maintenance, vacancy, water, taxes, insurance etc.