The afternoon winds are anabatic. (I ignored the bit about cold mountains).
Katabatic winds happen in the evening and do not usually create such strong valley winds.
no idea- locally it is called Le Joran- as it get colder ans denser at the cold top it creates - a vacuum. And 300m is a very very long way off shore on a paddle board when that happens- whatever it is called. When you are dead it doesn't really matter what the correct word is. (I have seen dead bodies- blown from north shore to south). A similar wind is called Le Vaudaire on the Léman.
The Jura montains are right behind the lake- and the difference in temps late afternoon can be more than 10C in a very short time- creating kabatic winds indeed- which can be very violent and happen VERY fast.