Theyattract bugs at night and then mice underneath.

Carpet cleaner stated that carpet was so deeply soiled, stains could not be removed with a steam cleaner.

My overall point is this:  real estate, land, soil, whatever you want to call it is the only thing you should be putting cash into.  

These would include not allowing dog to dig in yard, no damage or soiling in the house, house/potty trained, etc.

That looks like shrink swell soil issues.

Soil tests, aquafer tests, etc? 

You should also look at google 'terrain' map or some town flood zone info and ensure that you will actually be able to re-direct the water to a lower elevation, or buildup grade around building with some compacted top soil.

Aerate the soil, level out the holes and add seed and water. 

If you do crack or break a piece of trim don't panic- glue it back together I've even been successful with just dry fitting them together and nailing in placeI like to under cut the wall so the new floor will fit underneath the drywall or plaster.

Any scrape and it’s beige wood look underneath.