Just a quick comment related to this:
it would actually make things easier if the help system at least told you *how* to save searches.
Quoting from the Nautilus help file, chapter "Searching For Files", section "Saving Searches":
Nautilus searches can also be saved for future use. Once saved, searches may be reopened later. Figure 6-12 shows a user with three saved searches, browsing one of them.
Saved searches behave exactly like regular folders, for example you can open, move or delete files from within a saved search.
It does not actually say *anywhere* how to save a search, i.e. "To save a search, go to File>Save Search As..."