I noticed that the cable is very loose on the slide where the gouges are. That in itself indicates a problem with the slideout. I have the same type of slideout on my Sundance 5r. It's called a Bal-accuslide. My slideout was running out of square with the opening and tearing up the rubber seals so I took it in and the manufacturer "Heartland" covered the repairs under warranty.
Your manufacturer should also cover the rapairs on your slideout, as there is obviously something out of square or bent within the mechanism causing the gouging and loose cable. I also noticed the roof of the slide is creased inward at the edge which may also be an indication that it is out of square.
I found that contacting the manufacturer's customer service department and speaking with a rep with my vin number helped to get the ball rolling for an authorized repair at my dealer. Sometimes dealers will hee haw around for weeks before even looking into the repair and contacting the manufacturer for authorization. Providing your dealer with the phone number of the factory rep that you spoke with may save you a lot of time.
Keep us posted as to how this ends up. We all like to know how different manufacturers stand behind their products.