I had a contractor (whom I trust) look at the house and he suggested that I replace all the dry wall, electrical, and plumbing (as well as paint, carpet, windows, etc) and estimated 50k in repairs.

Yes there were kids in there and some pit bulls (violation of lease).The kids took tooth paste and wrote all over the walls in their bedroom upstairs and let it dry.

They were not designed to be dry like a poured foundation.

But the job was poorly done, and the soil under the slab apparently isn't very stable so now I have a floating kitchen, with cracks (interior and exterior) that randomly widen and shrink.

I don't currently own any properties yet, but I feel like this is a good but cut-and-dry plan.

Things may have changed as this was a year and a half ago but I was left high and dry.

I bought an apartment that had the Urine smell issues, pulled all the carpets poured buckets of bleach on sub floors and washed walls with it too, opened window's, let air out and dry for days.

Ideally, it only means being able to take slimmer deals when juicier opportunities dry up.  

If I know Rich people (in The Netherlands) they would just keep going to court, just to bleed you dry on attorney fees and force you to sell cheap.

Some people (Clayton Morris) make it seem so simple and estimate rehab costs from 20-25k which includes a new roof, new electrical, plumbing, boiler, water tank, windows, dry wall, paint, carpets/flooring, etc.