would also like to be able to fly an approach on instruments in extremis
Socal
You and I normally speak the same language
He did add the word "extremis" to his line meaning if all goes pear shaped.
People are very imperfect and with the best will in the world DO get into stupid situations.
So yes drum it into the VFR pilot "cloud !do not touch as they are nasty and likely to bite your head off".
But sadly many do hit awful situations and then you are left with your own abilities and skills to save you.
In that situation a VFR pilot with no instrument ability or nav aid knowledge doesnt stand a chance.
A pilot with some knowledge albeit limited stands a better chance.
IMO such a pilot just trained to fly on instruments and taught nothing more than tuning setting up and flying an ILS would with some radar unit to guide him to the right point "probably" be able to survive and I stress the word probably. A lot also depends on whether he could hold the plot and not freak himself out ie panic in the process.
Overload is the final killer. The point at which overload hits depends on so many things, experience, knowledge, natural ability etc and that runs right through to the most experienced of us. The only difference is our overload level is much much higher.
Pace