<< What is bugging me a lot (in Windows 10, with all the recent Scribus versions) is that positions and sizes of all sub-windows keep getting lost. >> Usually positions and sizes (if held) are held in a preferences file somewhere, not sure for Scribus and where it would be held in Windows (and if it varies depending on versions of Windows). But I have seen a number of issues with older programs on newer versions of Windows, where that preferences file is not held in an area Windows (no longer) lets a non Admin user write to and in a couple of cases some "locked down" corporate units with further restrictions. So the preferences file usually gets set up at installation time with defaults because admin rights have been used to install the program but there after it becomes a read only. Presumably someone with more knowledge of Scribus can confirm where these preferences are supposed to be held. Has it ever remembered size and positions on Windows? If so which version(s) of Scribus on which version(s) of Windows.
<< What I find especially nasty in Windows is that it does not automatically refer mouse-wheel movements to the scrolling list the mouse is over, but you have to click explicitly into the list before it is able to read mouse events. >> +1^2 K.