I think the ftp-server as it is atm lacks of a solid user rights management. I'd like to have the option to grant different users or user groups different types of access (read, write, view) to different/specific folders of the mounted USB-device and the option to easily add/remove access permissions.
You should be able to create groups and assign users to them and choose different root directorys for them. E-Mail notifications and an overview over (current) ftp-server-activity on the main status-page would be great too!
And some auto spin-down function for idle hard-disks!
But great MOD of Tomato so far, thanks for all your effort!