Filing IFR for flight outside of controlled airspace?
I did my FAA IR during the summer and now back in the UK I know I can file airways on N reg but I'm slightly confused about the whole business about IFR outside of controlled airspace.
Say I file a route that crosses mostly class G and through some class D zones but not in class A at all how will the file plan be treated?
Will it be as if I've filed VFR in the sense that ATC units along the way probably will not have any knowledge of my existence or will the units at say the zones that I wish to transit know I'm coming?
Is there actually any difference between filing IFR or VFR when outside controlled airspace and if not is there any point in filing at all (above the advantages of filing a normal VFR flight plan)?
Those are just a few questions that I have in my head at the moment but I'd appreciate any general advice on the subject of IFR outside CAS and perhaps people's views on whether or not it's a safe and viable way to operate an aircraft.