V long, v garbled reply follows, as I am surrounded by DCs.
Caveat: I used to be in charge of the CAPES courses in my uni. I resigned from that responsibility last yr for reasons of principle. So I am no longer as knowledgable as I was. Nor am I able to be very positive about the new system, I am afraid.
You need to have an M2 (Masters, 2nd yr level) to validate yr CAPES now, so even if you pass the CAPES w/o it, you won't get the benefit of yr concours until you pass the M2.
Yes, stagiaires are now thrown in at the deep end, teaching full time with little to no help. Many are cracking up.
CAFEP used to have same syllabus as CAPES, I presume that is still the case. One key difference in the new CAPES is that there is now no real syllabus, so IMO it is even harder, because more random, to prepare for than before.
No need to be RC to take the CAFEP, though it might help with the cultural aspects of integrating a RC French school.
There are, however, VERY few posts available for the CAFEP, so it's much tougher to pass in statistical terms, IYSWIM.
You do indeed need to know how to approach, structure, present things the French academic way, so in fact doing an M1/M2 might help with that. The CNED course will not give any info for non-native French candidates, it's sink or swim. The CNED course is also sometime a bit hit and miss, IME.
The calendar is now bonkers, so you have to take the CAPES written papers in Nov, prepare for the orals and do mini- stages in schools over winter/spring, take the orals (if admitted) in late spring, as well as writing your M2 mémoire, all in the same year.
Yes, you can be posted abslolutely anywhere; for newly qualified teachers, that is often the grimmer Parisian suburbs, but it can be the North, or sometimes remote rural areas too. Rapprochement de conjoints is meant to work, but the rectorat often refuses it (it happened to us when we moved from a DOM for me to take up a lectureship in SE France: they expected my DH to remain in the DOM, although we had a 4mth-old baby).
In response to your original query, I moved to France (well, a DOM), after my MA in the UK, did a DEA, then took the CAPES and Agrégation, followed by a doctorate. It is possible to integrate, many a British person has, but l'Education nationale is complex and you need to know your way around it, I think.
Fingon, I suspect yr uni in France advertises its courses because one outcome of the reform is that they are now all in competition, trying to get people to take 'their' Masters rather than the neighbouring university's one. Given the complete balls-up of the way the reform was led, and the deteriorating working conditions for teachers, student numbers are plummeting, and if the Masters courses die, University depts will die too, so the heat is on. I don't know if it means it's actually easier for foreigners to take the course at that university.
If you have any other queries, I am around tomorrow and it'll be quieter.
PS. have you looked at teacher's pay in France?