All that I mentioned are financially compliant for mortgages, they are accurate using the correct formula on a 360 day year. 

I've seen them require new driveways, garages, concrete pads, etc., which can add up to be really big bucks that we investors wouldn't normally ever spend (who cares about driveways?

When these note were made can be an issue, they will need to be compliant.

Concrete drives, patios, foundations, etc.

All good, just be aware your contract needs to be compliant if you're zapping out of state properties.

This is a ground floor unit so the subfloor is a concrete slab.

A permanent foundation is a concrete block perimeter around the home.

He lays carpet, fixes furnaces, sinks, paints, even pours concrete.

The system is built into the concrete slab but unsure if it leaks.

i have had similar situation before. just let them go. the sooner you let them go, the sooner your current problems go away.the last thing you want is to piss them off and they pour concrete down your pipes.