Plastic lumber doesn’t have the strength of real wood, and needs support.
Clean up the sawdust and wait for them to die on their own.
“Soil filtration” is caused by carbon particles, and it’s not easy to get out.
You can patch the hole yourself if the machine still works well.
Wait for a dry day, then scrape, jiggle and pry.
The problem could be the paint, but a small area can be dealt with by creating a gap for expansion.
If water is not seeping through, you can just clean, patch and repaint.
The problem is probably the spring balances, which have to be replaced — if you can find new ones.
If you have extra carpet, here’s how to make the repair. Or you could call in a pro.