Water comes out from the holes. If holes get clogged you can remove the black tube on the bottom and remove any debris.
Rolls back automatically
It's not available in the store. It has to be ordered and then shipped to the store for pick-up.
It probably will be damaged over time by freezing weather or severe sun. It is only some kind of rubber/plastic material. I rarely get freezing and snow, so I leave mine on year round. We rarely get freezing weather and snow where I live
Installed mine last fall and it is in fine condition this spring. I expect it will last at least two more years.
I have 6" gutters and downspouts and this fit fine.
Yes they roll back up on a level ground. They extend to approximately 40".
I have 6" downspout and they fit fine. In your case you could wrap the excess around the downspout.