1.
How to move downloads to new location
2. See
How to Change download location (click on link)
3. See
How to Change download location (click on link) (specific for folders)
To find the incomplete files, go to Library window & select incomplete folder & press Explore button. This will open the folder for you. The video might only be missing end credits.
For fast & easy access, go to your LW Library window, select Saved Files folder & press the Explore button. Sample image here:
Using Library Explore button to access downld folder (click on link) & the folder will open up for you.