You can't expand any panel to full screen in Resolve 16 like you can in Premiere Pro. You can expand the viewer to full screen with cmd/ctrl-F, and on the color page you can also get different viewer expansions with alt/opt-F and shift-F.
Beyond that, if a panel can be hidden, it's listed under the Workspace menu->Panels in Workspace, or by simply ...
I figured it out. The commands you're looking for are:
End to Playhead - in Application/Trim/Ripple
Start to Playhead - in Application/Trim/Ripple
Put them on some shortcut that is actually working on the german keyboard.