The same sick hatred and contempt toward everything that is "not ours".
This attitude is rather common among the expats living in Poland who come to post on this forum, not only was it typical for Sobieski (Panie, świeć nad jego duszą!).
No. Word `Luzica` is of Slavic origin. Very old word, ancient. Its `spoon`, literally.
This is perhaps quite close to the truth, Crow. Speaking precisely, Luzica takes its name after the land which is full of water and damp. You can also recognize the same root in the Russian word 'ług" which means 'acid' or 'acidic liquid/water'. This root is also present in the Polish word 'kałuża' (puddle of water). If you add 'ka-' to the word 'Łużyce (the Polish name for 'Luzica'), you get the word 'kałużyce', a very similar one to the word 'kałuże' (puddles), 'kałużyce' meaning 'big cuddles', although the latter word has disappeared from usage. And remember that in the early Middle Age period these parts of Europe had much more water than thay have today.
Of course, 'łyżka' may have exactly the same root as 'kałuża' (tool you used to take some acidic liquid as were probably ancient soups into your mouth).
The name "Sorb" is not related with the name "Serb", although sounds akin, and although these both tribes were and exist so far as Slavic.
I'd say they are closely related as it is very easy to imagine a German saying Sorb rather than Serb. Notice that in their own languages the 'Sorbish' people call themselves Serbja
(Upper Lusatia) or Serby
(Lower Lusatia). 'Sorbs' is a German name denoting a Serb living in Polabia which land was not German, but Slavic in the early Middle Ages.
"Serb" most probably meant 'kinsman' in proto-Slavic. This meaning can be distantly traced in the Polish name of 'pasierb' meaning 'stepson'.