It's about removing limescale, isn't it? This should be done with a sense of proportion: if there is a lot (little) limescale, a longer (shorter) soaking time. For example, I would soak overnight and see if it is enough to remove the limescale. If not, repeat. Lime cleaner is probably too aggressive for the plastic containers, hence the vinegar water in the instructions.

Yes, there is a container for cooking rice...but if it's small enough for up to 2 portions, the self-cooker is recommended.

Switches off automatically when the timer has run out. Unfortunately no, you have to make sure that it has enough water.

According to the information I have, Swiss plug. However, if the plug is European, a mini adapter is delivered with the product. This does not change anything in its use and the plug is only slightly longer.

Unfortunately, the manufacturer does not mention the materials of the product.