Hi Milbo,
the client wanted a half-width slider for just one category at the end of the shop entry page. The other half should have been filled with another custom module. Therefore I added these in the view.html.php. This worked with no problem, but the slider module itself didn't do the job as expected. So we're back to normal with this page.
But the problem with the overload still persists. We're really, really at the end of our wisdom.