His opinion was that the pipe itself was fine, but the problems occurred with the plastic fittings that were sometimes used. 

After this was done we put down 14mm plastic under the house as a moisture barrier.We dug a French drain around the front of the house back to the creek to help with any moisture issues under the house.While we were under the house we also replaced all the plumbing with brand new pipes.Both bathrooms have been completely renovated with the master getting a full custom tile shower and the other bathroom getting a soaker tub with custom tile surround.

you obviously have some siding & J channel missing.the latter is cheap as is plastic brick molding to replace the wood rotI would then use the plastic molding product 3-4 inches to frame them & secure the siding for now.here is a pic of a window my guy re-framed with plastic brick molding (bottom piece is not yet installed) & a sliding door with plastic wood (3/4 x 3inch) look planks ready to go to better interface with the siding fit. 

The picture is of one in my house, but the one available is still in the plastic.

I have had this advice of a 6 mil plastic barrier in crawl space too. not for fungus but to decrease moisture.

He did tell me though that I would also pay $200 to have a separate crew install a plastic covering on the roof from the inside of the house to prevent debris from falling through inside.

However, if i paid someone..200 bucks would be fair, and id let them keep the old heater as scrap. 500 is a bit much, unless there exists some sort of major surgery needed to replace the old one.

Just drive to a high-traffic intersection and count the number of these hastily made plastic signs.The "BSI" matters because it is direct evidence of under-capitalized amateurs trying to get into the game.

I've also just learned about inserting a new plastic pipe inside the main and epoxy lining all the pipes.

Brain surgery and divorce has taken my credit to the pit.