Mike,
Power cables generally have 2 ratings.
Yes. Just like the Austalian/NZ cables, European cables are rated 300/500V, 450/750V or 600/1000V. Flexes are 300/500 or 300/300. These ratings are not universal: Americans have their own and apparently the Russian do too. This really is rated 660V, which I take to mean 380/660V.
Using this sort of wire in a Distribution system would be frowned upon!.
Huh? That's not the case in other places.
It is of course preferable to use armoured/ neutral screened as it's safer and makes it more difficult to tamper with the cable. This has to be weighed against the increased cost.
You can use conduit, but it is a practical consideration, not a safety consideration unless the manufacturer states that the cable needs to be protected from mechanical damage. Some cables have to be in conduit, others don't.
