And we wonder why the regulators are so anti the rating.............
Well it is not for the reasons you imagine it to be.
Maintain VFR and either go back to get under the layer in VMC or divert to somewhere you can land at within your licence and rating privileges. If you can't, declare an emergency. It's black and white. Sorry if I am being dense, but what is "grey" here?
If you are following a milk float at 10 miles an hour along a 3 mile stretch of single carriage with double white lines, nothing coming the other way and a clear view, of course the correct thing to do is to stay behind the milk float for 3 miles at 10 mph.
I always remember I got asked that question at the end of my driving test - I told the examiner that obviously the correct answer was to stay behind the float but if it were going that slow and I had a clear view I would overtake - I passed.
I think pilot's are required to display a certain level of intelligence, presence and ability to assess situations. I think that if I arrived at my destination to find a thin overcast, which had been forecast as broken or scattered when I set off with a METAR showing perfect conditions below, I only had an IMCr, and I had done my home work on the MSA I would make a decision based on the facts as presented.
For those reasons I dont understand the point of the presentation to which you link 421C. A pilot with an IMCr or IR is capable of doing some pretty stupid things. The evidence is that an IR doesnt make him any less immune - infact the evidence is that he is far more likely to kill himself.
As others have said rules are terribly important, and on the whole flight safety rules exist to protect us from ourselves, BUT equally as others have said, you are the commander, you are in charge of the flight and there will be times you must make an intelligent assessment of the facts.