No, the printer can NOT save directly to a NAS, it needs a computer that receives the scan and saves it from there to the NAS, for example.

Yes, it can. With the supplied software "Epson Scan 2", you can specify the file storage location before scanning and also set it as the default. With the "Epson Scan Smart" software, two more clicks are required, but it can also save to the Synology DiskStation.