Foxmoth, Yep I have VOR, ADF , GPS on my IR. They're all quite easy to use.
An Airway doesn't need to be in CAS, at least not in this part of the world. The Airway has a minimum altitude assigned to it, this may change at various DME points along it's route to ensure clearance from terrain.
While we usually follow Airways inside CAS, since CAS usually also means surveillance airspace we often get direct (random route) tracking.
In this part of the world we could not operate outside of controlled airspace without Airways. There's far to much cumulo granite about.
There's never been an issue with traffic conflicts on an Airway outside of CAS.
A, the traffic on these routes is never that great to start with, B all IFR flights are on a Flight Plan and IFR flights are advised of other IFR flights and where necessary each flight co-ordinates with other flights to ensure separation.
While the perceived risk of collision with another aircraft may be higher the very real risk of collision with cumulo granite all but disappears.
How do you go point to point outside of CAS and no Airway. Are you flying from nav aid to nav aid? If not how do you quickly and accurately pin point your position? Is the nav aid coverage that good every where in the UK? How do you ensure safe terrain clearance?
You mention radar assistance, that to me infers you are in controlled airspace, is that so? There is no radar assistance outside of CAS here.
Due to the topography there's large parts of NZ that don't have radar coverage so no chance of radar assistance.