It would be great to integrate the most useful keyboard shortcuts into Nautilus itself, as it is common in most of commanders (Krusader, GNOME Commander, Midnight Commander etc.).

There are my proposed shortcuts (others you can propose in comments below):

F3 - quick view of selected file(s) [*]
F4 - edit selected file(s) in default text editor
F7 - create new directory (mkdir)
F8 - delete selected file(s)

[*]:
There is Gloobus project in progress, which seems very useful and helpful. What about integration into Nautilus?
https://launchpad.net/gloobus