How do I use my own folder structure with Shotwell?
Solution 1:
You have to do two things to achieve your four goals.
First, don't use Shotwell to import new photos. Import them with Nautilus to wherever you want to keep the pictures.
Second, change a setting in Shotwell. Edit/Preferences/Library(tab)/Import photos to: and select 'Other', then navigate to where you store your photos. This should be a drive that mounts automatically whenever you login. Check the box 'Watch library directory for new files'. That will automatically detect changes as you add or subtract images using Nautilus. The 'Importing' settings are irrelevant. You will not be using Shotwell to import images, so no need to change them.