I am German. Can I apply the hints for style or story-building given here, or by English authors, without a second thought to my own work written in German? Or are there differences in how style or storyline is understood by readers in different languages or cultures?
Writing style, in that a huge portion of it involves choice of how you word things, varies greatly from language to language and culture to culture. For example, I meet many people here in the US who have serious issues with my letting my son read "The Adventures of Tom Sawyer" by Mark Twain, because it uses a word for persons of color that was normal and common in Mark Twain's time, but is considered an epithet in America today. (Ironically, Mark Twain was one of the more progressive people in his time when it came to race relations.)
Story lines are about the same. The story line itself may be universal: striving to meet a goal, falling in love, etc., how it is interpreted by readers will depend a lot on cultural context: i.e. the reader's beliefs and experience and how that makes them view your setting, characters, and plot. Sometimes, they get so hung up on the setting or a particular belief of a character that they never even notice the plot.
This doesn't mean that you can't write for multiple audiences, just realize that they are different audiences, write well and let the marketing department figure out the rest. ;)