If the kitchens and bathrooms work , dress them up , thats all .

We fear the requirements of a subdivision, such as roads will not only be extremely costly but also damage some of the hay ground.

But the property is a duplex and so there's no way to know which unit is doing the damage.

The damage done by leaking water heaters is surprisingly terrible.4.

We have 45 days to establish an itemized list of damages and to refund $$$ to the tenants. 

However, the renter does have to follow basic rules regarding noise, cleaning up, no aggressive behavior, no property damage, etc.3.

May be time to take an Evaluation Video with tenants in the video, showing all the improvements.You can then use this video for any damage charges when they move out.

What sort of damages can they get?  

I've had a few contractors offer quotes for installing push piers and lifting the house... all for over $40k, which to me seems like a huge cost for leveling, which won't really even be noticeable (although I understand it will mitigate any future settlement and further damage).

Look for signs of structural damage, mold, and pest infestations.