Cleans and keeps the solder points clean. Prevents oxygen from reaching the solder joint

Try searching for hall effect Controllers. They will be more expensive, but don’t need sliding surfaces or easily failing parts.

I go by: If you are not sure you need a good one, buy the first one for cheap. Of you break it, buy a quality one. You obviously need it.

There will always be new malware. Just update regularly and use your head. Don’t worry about it too much

Mine is not hearable from the inside and only hearable on the same side of the house, but I guess it depends heavily on the model. I. The summer it only runs for hot water - maybe 4 times a day.

I would say ~10 years is normal for a murder in Germany and other European countries. I don’t know about current Russia but here the idea is jail time should lead to rehabilitation and a bit of punishment. In the US it is much more focused on punishment.