Your English is much better than my German ~smile~
In nUi5, you have to hand edit the layout files to change the location and size of elements though you can move the action bars without doing that. To move the bars, try using the command '/nui movers' to unlock them and then drag them where you want them.
If you want to change the size, or orientation, of the bars, you need to edit [
Interface > AddOns > nUI > Layouts > Default > nUI_Layout_Default_Dashboard.lua ] and locate the section for the action bars... there you can change the button sizes, number of rows and columns, etc.
The reason you can't find the options for nUI in the addon control panel is that nUI5 does not have a built in GUI configuration tool. nUI6 will fix that. There are also plugins you can find in the "nUI: Enhancements" section at
http://files.nUIaddon.com that allow you to change nUI options that way.