Frog,
I find it hard to reconcile your argument
Flying IMC intentionaly should require an IR,
with the fact that you are teaching an FAA IR in France
I don't agree that "Flying IMC intentionaly should require an IR", but if I did, then I imagine that I would think that it must be a JAA IR for a French person.
In any case your main issue seems to be with IMC trained pilots flying in IMC but declaring that they are VFR. This does indeed seem stupid, but none the less, the problem would be eliminated overnight if the rating was made Eu wide...the problem will just disappear, as there would be no reason to do that.
dp
(From a country also without an IMCr
)