Korinthenkacker = currant shitter, used for nitpickers and such

Torfnase = turf nose, synonym for idiot

Blindfisch = blind fish, synonym for idiot, also a popular insult for referees ;)

Vollpfosten (or Vollhorst) = a complete post/stake (or Horst...yes, that's just a name), basically means complete moron.

The other answer will take a while to write.../o\