How was the flooring attached? Glue? Nails?
Did you have any other option on the plastic edge piece that I see on the slid?
Could you have used a strip of wood that is normally used between carpet and tile?
It looks like the slide doesn't drop down into place flush anymore. I see a lip between the slide and the inside floor.
They have teflon strips you can attach under the slide from the outside at 3 or 4 places that will reduce scratching the floor.
Or you can buy a set of these slickers and may be a little better.
Slide-Out Slicker Protectors
More on RV Slickers