Mirko-
As for the EDIT links belonging to the sections, I would expect to be able to edit an entire section including the sub-headings after clicking on such an edit link. (see http://test.wikipedia.org/wiki/Donau-Ries - after clicking on EDIT next to the HISTORY section the edit screen includes only the heading "History" and not the sub-headings below)
This is a bit of a philosophical question. IMHO sections should not be as short as they are in the Donau-Ries article. The text is only 6400 bytes, yet there are 11 sections, that's 580 bytes per section. The whole history section has
Early history Ancient history Celtic and Roman peoples Germanic peoples Oettingen wars Newer history
IMHO these subsections are unnecessary unless there's actually a substantial amount of text in each one of them. Hopefully, the TOC and edit links will help us find the right balance in terms of individual section length. With longer sections, you don't want the [edit] link to load all the text within that section and subsections, because you'll have the same problem as before: too large blocks of text.
Regards,
Erik