The insert grate is thereby

The steriliser in question cannot reach a temperature of 121°C. According to the information available, it can set the temperature between 30°C and 100°C, which is insufficient to sterilise petri dishes at the required temperature.

I can't say anything about sous vide. Cooking sausages and keeping them warm works, heating punch or mulled wine and keeping them warm works. The appliance has a switch for continuous operation.

Since it is noted in the description that an adapter should be included, I would contact customer service :-) Otherwise you can find an adapter here on Galaxus: Schönenberger Fix-Adapter SchuKo-CH (Type 12, Schuko)

For this, you should contact the manufacturer directly :)

It seems that this model does not have a drain valve. The following alternatives would normally have one: https://www.galaxus.ch/fr/comparison/260705-20128220-260707

No, you have to order the juicer separately.