I have read online that I technically have possession of the property until I return the keys.

(I assume it is because you still must pay the last of the mortgage on year 30 and technically the loan balance will be 0 in year 31? 

Technically yes since there is a deduction it must file a return. 

I went so far as to buy a dehumidifier so he could use the basement for storage, replace the screen his dog damaged at no charge and other little things I don’t technically have to do to make it nicer for him  Now I feel like he’s taking advantage.Now the reason I’m considering giving in. 

Due to geography though all in Cincinnati, 2 properties (42 units) are with one management company and the third property (22 Units) with a second.My Los Angeles business is a cocktail of deeply technical and slightly creative but also with an intensely high level of client service.

In general, if you don't start working on an area and opening it up, the inspectors don't know what's there and technically neither do you -- so there isn't a need to update. 

I told him that it look terrible and we needed to re-cover up that old brick, so I asked him to build a light weight wooden hearth, and he wanted to charge me for it.There are lot of other places, where he remodeled, and it is technically functional, it just looks like really shoddy work.

Lion (leader, in charge), Beaver (detailed, technical) Golden Retriever (mild and loyal) or Otter (fun and friendly) . 

and after 1 year, you need to find a new tenant (so technically vacancy would be 1/13 months). 

I had to go back to an employer-based job a year later, but I did it in the field of technical writing, which was the new direction I wanted to go.