In KDE4 I like
1) the context-menu (right mouse) a) copy and b) move
2) the KDE apps: knotes, kaddressbook, konqueror (if this is not mantained at least try to port some features in Dolphin)...
3) system tray also for gtk apps

Thank you
Bertoldi

Which of these did you not find present in Plasma 5?

fbertoldi wrote:1) the context-menu (right mouse) a) copy and b) move

In Dolphin you can enable this in "Configure Dolphin" → Settings → "Copy To / Move To Entries"

fbertoldi wrote:2) the KDE apps: knotes, kaddressbook, konqueror (if this is not mantained at least try to port some features in Dolphin)...

KDE PIM is ported to KF5 but I don't know if those apps are part of that. Also, this is not very specific

fbertoldi wrote:3) system tray also for gtk apps

They should be shown alongside the other tray icons as of Plasma 5.5 or Plasma 5.6, if you're refering to the legacy xembed stuff.

KNotes and KAddressbook are fully ported to KF5 since Applications 15.08.

Thank you!
1) is solved
2) is partially solved, because my distro (Pclinuxos) has not yet kde-pim in kde plasma 5
3) tray icon : sincerly I don't undestand (maybe for my imperfect english). The icon tray in KDE 5 is a "black hole" for the gtk apps (or maybe for the non kde apps), while in KDE4 I can use the system tray for non kde apps, like Amule.