What's STU and ZUR?
I assume ZUR is actually ZRH--Zürich, but I can't figure out STU. Stuttgart (STR) maybe?
Stuttgart->Pullach: ca. 3 hours by train
Frankfurt->Pullach: ca. 4 hours by train
Zürich->Pullach: ca. 6 hours by train
Flying Lawyer's master thread on rail travel in Germany may answer some of your questions:
http://www.flyertalk.com/forum/europ...l-germany.html