Is it possible to edit the default views like "Manage Nodes" so that there is no grouping, and to add columns?
Yes, you can disable grouping
As well as add additional columns of data to the grid
I saw the no grouping in the list there, but it goes back everytime I leave the page. Can I set it to stay that way?
The settings should persist, though I did stumble upon an instance where they did not for some reason. I found that if you make your changes, then click on "Admin" in the top left, the changes persist. If you click on "Node Management" next to it, they do not, so your mileage may vary.
Mine goes back to vendor no matter where else I go.
