Hi Manuel. If you allow...
Navigation addon I use now the navigation addon as a modul on position left.
Navigation Addon is intended only for single-page Landing Page, to use anchor links. Not that you can not build with it navigation for multi-page site, but it is extremely not convenient. And some things are not fulfilled in principle with this addon. Instead, use the standard Joomla menu module plus some JS encoding for the dropdown list. Or third-party menu module having a dropdown list on board.
On SP PB pages, you cannot use the left and right position of the template modules.
Such a layout must be fully built inside SP PB Page using one global section divided into a column for navigation and column for content and inner sections in content column. To output the side menu, use the Joomla Module Addon with the "module position" mode. Create your own position for this. For example Custom-left.
The Slideshow works but not in Full width.
In this case, the full width setting does not matter, since the width is limited to the page container and the width of the section. Do not use the module. Place the slideshow right on the SP PB page and switch the section in which it is located to Fluid Width.
Here is layout exemple
