In my part of the country, you have to put a mobile home on a cement foundation if it is not in a park.

The rear of the building has a ground level door to the first unit, stairs that go up to the second unit, and those same stairs make it all the way up to the third unit.

I rent a house (I live in the house), and when it rains alot, and the ground is saturated, a small river starts coming out from the foundation, runs down the cement stairs and goes down a drain. 

5. are there railing on all interior and exterior stairs?

As well as the stair railing needing fixed and a hole in the floor being fixed.

I am not a typical investor so not sure how useful my opinion is but here are the reasons I chose the ADU route. 1) It could become a unit where we live when we no longer can climb stairs.

Because it was not easy to install on cement flooring underneath the vinyl.My mistake. 

Things that we see as recommendations to fix after include:- cut back overhanging branches- add railings on stairs- fix cracked/broken driveways or walk ways- repair roof issues - clear debris from outside or inside- upgrade fuses to circuit breakers- repair broken alarm/smoke detectorsYou should discuss the inspection with your agent. 

Since I am just starting out with owning rental properties, I wanted to hear what experienced landlords would do in this situation.An older resident asked me to install handrailing outside the front door on the stairs.

I'm not sure what local people charge to shovel roughly 20Ft of sidewalk and 6 stairs leading up to the front door.