Question 1:
How to fix the DW Simplex Flickr get the message ” SSL is required!” ? 

It’s because commutation is sent to the http API address instead of https. Change all http://api.flickr.com/services. address in the plugin to https://api.flickr.com/services
I believe Flickr recently closed the http API. Open the widgets.php file in the folder path
\wp-content\themes\dw-simplex\inc\widgets.php. lines 197 + 218

Question 2:
How to create a new page with a left sidebar and text right ?

To do this, follow steps below:
Step 1 Create new a page-sidebar-left.php  file, then add the following code to your file:

<?php
/**
* Template Name: Sidebar Left
*
* @package DW Simplex
* @since DW Simplex 1.0.3
*/
get_header(); ?>
   <header class="page-header">
      <h1 class="page-title"><?php the_title(); ?></h1>
   </header><!-- .entry-header -->
   <div class="container-fluid">
       <div class="row-fluid">
          <div id="primary" class="span9" style="float:right;">
             <div id="content" role="main">
             <?php while ( have_posts() ) : the_post(); ?>
             <article id="page-<?php the_ID(); ?>" <?php post_class(); ?>>
                  <div class="entry-content">
                      <?php the_content(); ?>
                      <?php wp_link_pages( array( 'before' => '<div class="page-link"><span>' . __( 'Pages:', 'dw-simplex' ) . '</span>', 'after' => '</div>' ) ); ?>
                  </div><!-- .entry-content -->
             </article><!-- #post-0 -->
             <?php endwhile; ?>
             </div><!-- #content -->
           </div><!-- #primary -->

           <div id="secondary page-demo" class="widget-area span3" style="float:left;margin-left: 0;" role="complementary">
              <?php if ( ! dynamic_sidebar( 'sidebar-left' ) ) : ?>
           <?php endif; // end sidebar widget area ?>
         </div>
       </div>
     </div>
<?php get_footer(); ?>

Step 2 Log in to Dashboard > Pages > Add new, then select the Sidebar Left template in the Page Attributes section in the right hand side.
See the screenshot: http://prntscr.com/5jltso

 

Question 3:
How to make the slider autoplay?

To make the slider autoplay, please go to Dashboard / Appearances / Customize / Custom Code, and add the code below to Footer Code section:

<script id="auto_play_slider">
 jQuery(function($){
 $('.dw-simplex-slide').carousel({
 interval: 3000
 });
 });
</script>

 

Question 4:
How to make the footer extend to the full width of the page ?

If you want to make the footer full width, you can follow some solution below:
Solution1: Just full width footer for all the pages.
You can open the page.php or any page template file in the template folder then add a </div> tag above the following code: <?php get_footer(); ?>

Solution2: If you want to make full width for each page, you can use the page template. To do this, follow steps below:
Create new a page-footer.php file, then add the following code to your file:

<?php
/**
* Template Name: Footer Full Width 
*
* @package DW Simplex
* @since DW Simplex 1.0.3
*/
get_header(); ?>
     <header class="page-header">
         <h1 class="page-title"><?php the_title(); ?></h1>
     </header><!-- .entry-header -->
     <div class="container-fluid">
         <div class="row-fluid">
             <div id="primary" class="span9" style="">
                 <div id="content" role="main">
                 <?php while ( have_posts() ) : the_post(); ?>
                 <article id="page-<?php the_ID(); ?>" <?php post_class(); ?>>
                      <div class="entry-content">
                          <?php the_content(); ?>
                               <?php wp_link_pages( array( 'before' => '<div class="page-link"><span>' . __( 'Pages:', 'dw-simplex' ) . '</span>', 'after' => '</div>' ) ); ?>
                          </div><!-- .entry-content -->
                 </article><!-- #post-0 -->
                 <?php endwhile; ?>
           </div><!-- #content -->
      </div><!-- #primary -->

      </div>
    </div>
</div>
<?php get_footer(); ?>

Finally, log in to Dashboard > Pages > Add new, then select the full width footer template in the Page Attributes section in the right hand side.

Solution3: You can add the following code to the style.css file to make full width in the all pages:
#page { width: 100%;}