- how can I see that a screen/dialog is active? It is with the default theme extremely hard to see
- why is drag handle area impossibly small? When I need to manually resize a window (or column) I need to have the mouse pointer on the specific pixel of the window border, or else I wouldn't get the resize pointer
You need to change the window decoration
https://docs.kde.org/trunk5/en/kwin/kcontrol/kwindecoration/...
"Tip
For accessibility purposes, some window decorations support extra wide borders. If this is available, you can also choose a Window border size here. The large borders are easier to see for low vision users, and easier to grab for people with limited mobility or difficulty using a mouse."
Great tip!
I use "Dim inactive" desktop effect which darkens windows that aren't focused. You can configure the strength of dimming, so that difference active vs. inactive is clearly visible but you can still (somewhat) read the content of inactive window without activating it.