2. 4. and 5. were previously attempted, but users found this distracting or, in a few cases, that it could put existing documents in danger of being overwritten in case a similarly-named document already exists there.
1 and 3. might be possible, now that CUPS is finally Dbus-aware, so adding some support for this in CUPS-PDF too might not be entirely impossible, but it would probably render the codebase incompatible with older CUPS releases. Still, investigating this might be a good Summer of Code project. It would be useful for whoever attempts this to contact upstream and coordinate with him.
2. 4. and 5. were previously attempted, but users found this distracting or, in a few cases, that it could put existing documents in danger of being overwritten in case a similarly-named document already exists there.
1 and 3. might be possible, now that CUPS is finally Dbus-aware, so adding some support for this in CUPS-PDF too might not be entirely impossible, but it would probably render the codebase incompatible with older CUPS releases. Still, investigating this might be a good Summer of Code project. It would be useful for whoever attempts this to contact upstream and coordinate with him.