Hi
1 & 2) To change the background of these areas to a color you would need to use the color customiser which you can access in the toolbar at the top of the page
3) Unfortunately the portfolio can only be 2 3 or 4 columns
4) You will just need 2 different portfolio categories, assign the portfolio items to one of the categories, and then create 2 separate portfolio pages and in the portfolio asset options select the category you want to use
5) Unfortunately it’s not possible to have this social network yet
– Kyle