1 – i. Hide the InfoBar from the options for all devices.
ii. Set a bg color for primary and secondary sidebar areas (there are only two now, you can set a bg color for each. The primary will be the left or upper area.)
iii. On the sidebars and layout tab, at the bottom of the Sidebar layout option, check the Flow color to bottom.
iv. On the Content Areas tab, in the Content Area section, for the CSS+ box for the Content Area BG, add a rule {border-right: 1px solid black;} (or left and whatever color you need.
2. The spacing option works. Perhaps you set a value for the wrong menu – you can set Primary and Secondary menus separately.
3. See #1 – use the bg color for Primary and Secondary sidebars to set the bg colors for sidebars.