Customize create content page
Yes, it is possible. Firstly you need to read and understand the Drupal 7 Template (Theme Hook) Suggestions documentation to render and rearranging field items.To alter Title , Body, Save etc you will need to understand hook_form_alter, it is used for altering a form and hook_form_FORM_ID_alter is a smarter way to do the same as hook_form_alter.There is a cool hook_form_alter tutorial hope will help you.