Unable to select all text via shortcut with Okular preview loaded. I think this can be fixed by allowing focus for preview pane. I use focus follows mouse and expect that hovering over the preview pane sends shortcuts to the pane and if over editor component shortcuts are sent as usual. With preview collapsed there is no issue.
Thanks for the report, indeed a (known) issue. Last time I looked the problem has been that shortcuts from KParts (KXMLGUI-based) are registered globally to the app, so they will conflict independent of the focus set. And are only unregistered if the widget is hidden. But definitely needs another, longer investigation. *** This bug has been marked as a duplicate of bug 386265 ***