Examples include median sale prices, job stability for an area, which neighborhoods may be seen as up-and-coming, are they A-B-C neighborhoods, when was the roof and furnace last replaced, what type of electrical panel exists in the home, etc.

When it comes to units that you own, every bathtub, stair step, hand rail, linoleum floor, rusty nail, splinted fence, exposed tree root,  fireplace and electrical outlet is a potential exposure.

And the electric should run about the same (2-3k).

Will the basement unit have it's own water, gas, electric, internet, phone, cable TV services?

Unless you see bugs or have line-item expenses it's sometimes hard to see those items that you might see as a routine expense.3.)

To heat a large 3br apartment, electric heat would be really expensive, and those ductless wall systems I hear require a lot of upkeep/maintenance which I can't depend on tenants to do and would prefer not to have to be there once a month to maintain myself. 

If so, that’s a big plus, but you’ll have to pay the city something to tie in each unit.We spent about $100K for 2 tiny houses, furnishings, a/c, roads, electric, and septic.

You may want to way removing that wall with the potential for an inspector to come in and tell you that you are going to have to update the electrical wiring in the house or redo all the plumbing, etc.

It's hard to find honest and reliable "handymen," not to mention the issues you might have doing unlicensed work on electrical, etc.

They know the electric company or water will cut them off for nine payment, they know their car will be reposted if they don't pay.