So, from my limited scope of experience here are my take-aways:Vinyl IS 100% waterproof because it is 100% plastic (actually, it's probably not technically 100% plastic, but in essence that is what it is). 

Hi,My friend is building a ~600 sq ft ADU in So Cal/Los Angeles and is wondering what type of pipe might be best from a quality/maintenance/cost standpoint within the interior of the ADU (I realize that the line connecting the ADU to the sewer line might be HDPE or some other plastic pipe...)? 

For uppers, shimming can still be required, such as behind the steel support rail if the wall is horizontally wavy, or at the bottom of the cabinet if the plastic spacer they include isn't thick enough. 

Inside solutions like French drains, sump pumps, or plastic inside waterproofing might be fine for that 25-year storm, but the water is already getting in and damaging the foundation.

Have them regrade and put rock/plastic around the foundation to shed water away.

From your first picture there is a plastic pane that slides into place so that it can stay closed/locked and keep the dog (or other animals) from climbing in and out.

Is the exterior basement wall covered in plastic wrap?

Dishwasher was brand new never used I got it for $150 - stove was 4 months old it had been installed but the oven still had plastic wrap around the shelving so only the top was ever used - the fridge is the oldest but still less than two years old it was purchased from a very high end property for $200.I had my contractor build my counter tops, it turned out nice however you can buy ready made counter tops and just pay for fitting this would save around $500.Original kitchen

It took a lot of abuse from 5 years of college girls BUT it was made from recycled plastic bottles & the stains came out.

tell her, the next time she sees a 'bed bug' to save it in a plastic bag so that pest control can verify what it is.