BR's stared items are mostly my top used ones.
I like to hammer my metadata into submission.
Look at the ones by Kiwidude.
The Quality check finds issues with books metadata (and has a few Fixes)
Manage Series for us fiction readers. (You said Documents, so you are more into BR's type of use)
Find duplicates. Really handy if you use an Intake Library, to see if you have matches in the MAIN Library
If your old computers HD still works (place in a external case, if the mainboard is dead), and copy your Calibre Config folder to the new system. That HAS all your old PI and settings. Calibre will notify you that updates are available. you will have all your settings in place