Best way to integrate "customization" to the front page
As a possible starting point, you might use the Panels and Panelizer modules.

When you define a custom CTools page (using the Page Manager module included with the CTools module), you can define its layout and content.

Concerning your second question, it is also possible to edit the page without moving to the administrative interface, by using the IPE (In Place Editor) provided by Panels.

You should be able to find many tutorials about Panels, in drupal.org too: https://www.drupal.org/node/1857644