

If KDE works for you, do you use a preinstalled distro and which one?
Has largely worked fine for me on Tumbleweed.
There is/was an issue with launching some of the ‘K’ apps causing the desktop to hard lock. But this happens very rarely.
Haven’t experienced problems like what you’re describing though.
Haven’t experienced either of those issues. Have you tried to isolate KDE in those cases? Not sure how you’d do it with the deletion because there’s no Trash for the terminal, but you could try the copy operation and see if your device is still blocked when it’s finished in the terminal?
Those are both file operations so they don’t strike me as strictly DE-related.