First of all: punctuation.

Column widths will differ owing to average length of words.

I don’t think it screams a certain nationality, but Martin Majoor’s FF Nexus is particularly equipped for trilingual texts with a Serif, Sans, and Mix (slab) version. See more in this old thread.

Thanks for the answers so far, but i need quite a lot more material.
I was thinking along the lines of books or described examples.
What yiu gave me so far has helped out a lot.

Why not do some first-hand research?!
For instance, you could buy the top 10 magazines in a certain category, in the three countries, and analyze what fonts and layouts are used.

Read the typesetting section of The Chicago Manual of Style, for a start. Also, visit the countries and just look at books, signage, magazines, newspapers, and take lots of photos. Graphic design has a distinctly different feel in France, Germany, and England (and, of course, compared to America); you can then try to identify why it feels different.

My only aim is to design a font which works colleboratively with Turkish language. So, if you face with certain characteristics of unilingual typefaces, come with :)

@Nick Shinn:
For instance, you could buy the top 10 magazines in a certain category, in the three countries, and analyze what fonts and layouts are used.

Also, Google Books is a free resource - and it might well be useful to look at older books from different countries to get a feel for practice before homogenizing influences had a chance to change the typography of some countries. (Although, in other cases, the limitations of metal type or the economic dominance of some countries might have suppressed national styles for some time.)

One example that comes to mind is that in Britain, it was normal practice to insert a space between a word and a colon which followed it.

Also, I remember reading a claim that Italian, instead of hyphenating, uses superscript letters somehow, although I don't recall ever seeing this in an Italian text.

The one thing I remember from working in Germany is that the SPELLING of a word changed when it was hyphenated.
Nur die Deutschen

Not anymore. I assume you refer to the rule that the digraph ck gets replaced by k-k when hyphenated (Lücke → Lük-ke). This was changed in the last spelling reform. Now ck always remains together (Lücke → Lü-cke).

Danke Florian – didn't know that – bestens

I meant to say as well that the German language has much higher frequency of capital letters so some German type designers such as the genius Georg Trump made their capitals shorter.

or lighter, see: http://www.typophile.com/node/72900#comment-423873