You can change the headings font-family, color, line height etc http://prntscr.com/nuecoj everything except the font-size, unfortunately. Anyway, feel free to contact me if you need to change the size for the built-in element an I’ll help you with no problem.
To get the layout you sent make sure that wide layout is chosen in Theme Options > General http://prntscr.com/nueeb6 You’ll be able to change the header/footer/menu color from the appropriate sections of the ThemeOptions. If you want to stretch section bg edit row settings http://prntscr.com/nuefx7
