Should have re-pipe property: replacing old galvanized piping with PEX plumbing.

,it never went further than this but there is a millions reasons I wouldn't be aware that could eventually result in the property being the source of the health problems,or worse they could hire an attorney that could help put the responsibility on me,Do you guys always change all the plumbing on your rentals houses?

But that way you're at least covered a little if something major goes wrong in the first year with appliances, plumbing, or electric to save you those unexpected costs while you work to improve the cash flows.

My land tripled and I did the build out and plumbing and heating.

Often electrical and plumbing runs through the damaged wood, ensure that any repairs needed to these features are included, eg. a plumbing pipe has dropped, but it is old and will split if moved.Several months back I had a contractor working on a bathroom and another working on a roof on a 1910 Victorian house. 

We ran into electrical, plumbing and roofing issues.This was a complete gut and renovation.

The type of repairs also varies based on the loan type, here's some information pasted from (not my site) https://themortgagereports.com/18228/which-fha-203k-loan-home-construction-standard-streamlineThis is the work which is allowed via the FHA 203k Limited: Repair/replacement of roofs, gutters and downspoutsRepair/replacement/upgrade of existing HVAC systemsRepair/replacement/upgrade of plumbing and electrical systemsRepair/replacement of existing flooringMinor remodeling which does not involve structural repairsExterior and interior paintingWeatherization of windows and doors, insulation, weather stripping.Purchase and installation of appliancesImprovements for accessibility for persons with disabilitiesLead-based paint stabilization or abatement of lead-based paint hazardsRepair, replacement or the addition of exterior decks, patios, and porchesBasement remodeling which does not involve structural repairsBasement waterproofingWindow and door replacement and exterior siding replacementWell or septic system repair or replacementAnd, this is the work allowed via the FHA 203k Standard: Major rehabilitation, such as the relocation of a load-bearing wallNew construction, including room additionsRepair of structural damageRepairs requiring detailed drawings or architectural exhibitsLandscaping or similar “site amenity” improvementAny repair requiring a work schedule longer than three (3) months; or rehabilitation activities that require more than two (2) payments per specialized contractorImprovements that require a plan reviewerImprovements that result in work not starting within 30 days after loan closing; or cause the owner to be displaced from the property for more than 30 days during the time the rehabilitation work is being conducted

I did the work myself, minus rough-in plumbing, fully permitted in my “spare” time from a full-time job as an operations manager, a pregnant wife, a 1 year old, and 2 60lb dogs in about 5 months.

How old are the HVAC, Refrigerators, plumbing, etc?

I have also had to remove plumbing pipes due to a toilet not working for over 3 years.