Here is the answer to 3.
Keep Cloudy-grey (or the theme that began giving you the problem after update).
Put the following line into ~/.config/gtk-3.0/gtk.css (create it if it does not exit). You may have to reboot for the effect.
@define-color theme_unfocused_selected_bg_color #555555;
–substituting obviously the color you want for #555555.