I would do all of this before you buy anything.Also, your initial short term plan, as described, will probably the most expensive, most time consuming, and longest to complete potential plan you can choose....and, don't do your own rehab. 

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

We know this is a lofty goal, but by taking baby steps and calculated risks, we believe we can at least build a business from this, allowing us to leave our life-consuming day jobs. 

Showing is time consuming so we save that for much later.We ask how may animals, how many people, employer, income, where do you live now etc.

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. 

It wound up being a lot more complicated, expensive and time-consuming than I expected but it's finally done.

If it is demonstrable you contracted in bad faith, the contract itself would be void.If the contract clearly indicates you really have no intention of purchasing the property, you could be seen as acting as an unlicensed agent ... particularly if you establish a pattern of such transactions.Traditionally, in business, a wholesaler acquires a good, then resells it to the retailer - who in-turn sells to the consumer.  

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.

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