#1 is reasonable enough, but we'd need to remember to ifdef it conditionally. AA_DisableWindowContextHelpButton was only introduced in Qt5.10, and we try to ensure that Sigil will build and function with at least limited functionality back to Qt5.9.4 on Linux.
#2. I'm for anything that helps with moving Sigil toward better supporting a dark mode (however it's accomplished).
#3. The frame is quite important. It's the central widget. It's visibility or appearance, however, is not vital. I've no real feelings (good or bad) on this particular suggestion.
#4 Again, no strong feelings one way or another.
#5 HOW DARE YOU! I slaved for
minutes creating THAT icon!
But seriously... I hate icon work, I'd entertain reasonable replacement suggestions (as long as all three necessary sizes were supplied). To be honest, I'm not sure if I did that one or not (or if it's even an icon). I think I did the h* icon.
#6 I can live with or without this change.