OK... I've found some mods, that decreased my latency down to 25ms in Dalaran! But still have my fps-crashdown to 5fps! Even if I turn all the visual effects on minimum!
Hey cool.. a banana^^
Anyway... I also tried the config.wtf-hack^^! It just optimized my visual effects
I cleared the folder SavedVariables in my WoW-Account-Folder-thingermajigger... helped quite a bit