The one remaining is a 69 year old man with no job and some health issues.

However if you decide to build then I would suggest.1. look at their license status and any complaints filed against them.

Hi @David Fairall - here's how I'd order my approach:1) Health and Safety issues (ie, GFI outlets)2) Domino issues (ie, inadequate gutters that lead to water damage in the basement)3) Value add items (ie, fresh paint job and kitchen remodel)4) Whatever's left (ie, automatic sprinklers)As a landlord, I'd never want to allow an issue to exist that could jeopardize the health and/or safety of a tenant, which is why I'd address it first. 

How much time do I have to get things remediated before a tenent could possibly claim health issues in the courts eye?

We have moved and feel we are owed the money from April to May as we should be paying rent for a until we can’t fully use without it affecting our health.

Sure.The vast majority of us are mom and pops, but we have to put up with professional squatters especially here in NY. https://twitter.com/tonydwagner/status/1148442052851408897?

Along with a trust, you'll want Wills and health care directives and powers of attorney and whatnot. 

ESA is supposed to be for someone who, according to a health professional,  "can't function normally " without the presence of that animal.

ROE comes into play when I'm trying to optimize my portfolio later on.So I was definitely including PMI in my calcs to determine cocROI, but then started fumbling around with cap rates and got myself confused.It now makes more sense that I should not focus so much on that metric for SFH and small multi’s.Good tip to keep ROE in mind for overall portfolio health. 

Things like 401K match, health insurance, dental, vision - whatever it will go away.Union workers will have their union dues will go up.