I suppose that the OP has long gone by now, hence this is a waste of posting time, but for the record… My Tower & Lappy, being only with oS since May this year, are continuing to delight me with TW KDE Plasma5… as i [think i] have written elsewhere, TW KDE is giving me my best ever P5 experience [having tried several other P5 DE distros prior to trying oS].
My only regret, affecting Tower but not Lappy, is that after migrating Lappy, but before migrating Tower, i discovered Ruby Installer’s “Custom” option re DE [on Lappy i’d not noticed it & simply chose KDE], & so during Tower’s TW installation i foolishly acted like the proverbial kid in a lolly [aka, candy] store, by going “Custom” then selecting not only KDE but also GNOME & Xfce… purely for the geek-factor of having alternative DEs but without any sensible actual need for them. Whilst in the weeks since then Tower’s TW KDE continues to impress, there are several areas where aspects of my preferred Oxygen theming don’t work & the ugly GNOME’ish squared greyish window UI & boring icons manifest. None of that happens on Lappy, which uses identical Plasma settings as Tower… other than the fact that Lappy is “pure” KDE DE. Retrospectively i do regret my initial decision during Tower’s installation… but this is my error not TW’s, as far as i can see.
So, whilst i found OP’s litany of hassles upsetting to read, i do wonder if their experience might have been altogether happier had they instead chosen Leap KDE, or indeed maybe TW KDE… All too late now.