Need to repair newly installed pocket door

[lea]

Constructed new wall (lath and plaster).
Contractor installed 40"x80" hollow core pocket door and painted. One thin coat of primer and one thin coat of paint
The door was painted prior to installation.
Door leads from garage to the old work/machine shop into an extra room so we need the room to be secure.
I believe he made his own frame for the door and did not install a ready made frame.
Now there are 2 problems:
There is a 1" gap between the bottom of the door and the new hardwood floor allowing dirt to come in. (He says it I not his problem)
When the door is opened and closed the paint has been scraped off into the skin or heavy rub marks from one side of the door to the other on the garage side of the door.
Starting at the top of the door and moving down the rub marks are as follows:
15" down a rub mark 1" wide
21" down the paint is scraped off and the rub mark is 3" wide
36" down a single line
42" down a single line
52" down a single line
Contractor tells us someone came in and played with the door but they are they only one who touched it.
I know a lot about construction but not in this area.
Can they open the wall at the top and add a shim and then reinstall the track to drop the door?
If so how wide of an opening do they need? The plasterer was an artist and I hate to cut into his work but my painter
also an artist says he can fix it with dry wall so it won't show
What type of drywall should be used?
What can be done with the scraping?
Can the door be sanded?
If so how deep can we sand?
Thank you for any and all suggestions

 

[dovetail]

You should be able to adjust the height by turning the adjustment screws on the top of the door. You should be able to lower it a half inch by doing so. Generally speaking you want a 1/2" - 3/4" gap at the bottom of the door for proper air flow and function of your HVAC unit. The scraping is likely caused by improper fastener length when attaching the lathe. If the scratches are deep you'll be better off filling them than sanding them. All that said sounds like a poor job of installing the pocket door. I've installed many and never had any of the issues you are describing. My advice is a new installation.