Regarding Options>Custom> "custom files to delete and folders to empty"
First of all, you should be able to select all or multiple at the same time.
(that way, "Remove selected items from the list" has a purpose)
Second, you should be able to delete all files in the list.
After all, you can drag files from explorer into the window.
Third, you should be able to remove items from the list, WITHOUT removing the files.
I was under the impression this was similar to Spybot's Secure Shredder - I dragged a bunch of stuff from search results in explorer into the window, but I have to remove them one at a time - which will take hours.