The Problem was indeed the xhtml beein in version 1.0.
I converted the Paged to xhtml 1.1.
Unfortunately in the conversoin process some layout information got lost due to xhtml 1.1 restrictions.
I tried to recreate them in css.
Adobed DE behaviour regarding CSS entries it cant understand is a bit harsh. If such a file is encountered the entire CSS gets ignored. That might be something worth while adding to the epubcheck.
The bug with Text beeing cut in a Table cell, if there is more text that can be displayed on one page seems to be a bug in Adobe DE. Nothing i can do here.