When selected several notes in NOTE LIST should be able to define tag for all selected, delete all selected and so on.
Font size would be useful for those wanting to print their notes.
Options/[checkbox] Single click show/hide mainform from tray.
Some form of display default note list on tray click eg in Mynotes I may have several notes that would be displayed on tray mouseclick, as well as menu items.
I have also used Everpad, and apart from Everpad having the tray menu items list, Nixnote is far superior.