BB, you have posted a reference for a requirement for a training course, followed by one saying it can be "reduced" but you haven't found one saying how much it can bre reduced by. So, reducing it to zero is still "reduced". I seriously doubt the paragon of virtue called Switzerland would bust JAA rules after joining up.
Regards scaremongering, you have posted rumours about people having problems by not following what you call proper procedure but no references to actual cases.
Like I said, the CAA isn't happy about ATPL candidates going to Bongo Bongo Land for their initial CV test (presumably so that a failure is not recorded on their UK pilot record, enabling them to re-take it elsewhere later) but they can't do anything about it. Once you have the paper, you have the paper. This game is mostly about paper. Flying a plane under IFR is the (relatively) easy bit.
I can see that doing a JAA IR in say Switzerland could get one into a blind alley if one has only got a UK JAA PPL and wants to add that IR to that PPL, and the CAA refuses to play ball. But do they refuse?? If so, when have they refused - actual cases please.
I wouldn't do a JAA IR now anyway. EASA will take over FCL soon enough and then all bets are off. The IR (which has got harder year on year since day 1) cannot possibly get any harder under EASA, IMHO. What is sure to happen under EASA is that all this "we are in JAA but we refuse to accept papers from another JAA country" stuff will come to an end.