1) 24 days a year is the legal minimum
2) it's okay, quality-wise, and yes it's universal, the system is that you either can't avoid insurance or, if you are a freelancer, are legally required to take one. Sounds forced, but that is supposed to make it affordable for everyone. Let's not go into too much detail.
3) the weather is quite nice at times. Compared to the US, there is much more variety and much less extremes (like hurricanes or tornadoes). The weather strongly depends if we get it from the east or the west (more often the latter). West means oceanic, mild mostly nice summer, mild rainy winter - east means continental, hot summer, cold winter. That way, in winter you can get -20°C, but more usually around 0°C, and in summer it's around 25°C I'd say, going up to 34°C<, if we get it from Siberia. (Yeah Siberia is huge and gets 40°C in summer regularly).