We haven't found out either. It could be the power plug.

I find yes. The remaining water is really minimal and dries within 1-2 minutes. You should also keep in mind that it dries better when you pull it from the squeegee than when you push it. I had a large crack somewhere in the parquet, where the water penetrated and gave small discolourations around the crack, not very disturbing as it still looks natural, but just a change. (Maybe go over it with a dry mop at the end to be on the safe side). Because of the oil, it depends on the cleaning agent. Detergent dissolves oil and grease. So either add a little/gentle cleaning agent to the tank or re-oil the parquet often.

I would also be interested in that. Has the quality been improved? I have the first FC 5, which is really poor quality. Kärcher had to send me spare parts after the second use, because parts of the roller cover broke off during the disassembly necessary for cleaning. Since today, the fresh water is also running out. I've used the thing maybe 15 times

The wiping function is always there. If you only want to vacuum, you are better off with a vacuum cleaner.

Unfortunately, I could not find the desired part with the manufacturer's number 5.055-410.0 in the Galaxus range. However, you could contact customer support and ask if the product could be included.