A) The front page slideshow is a view block. You can remove this block from the corresponding region through the blocks configuration page or directly by the corresponding option in the contextual links
B) Can you please provide more information on what exactly you are trying to achieve? Please provide sample URLs and/or screenshots that demonstrate your goal
C) This can be done through CSS. Please check the following screen that demonstrated the corresponding selector: https://www.screencast.com/t/5N6bmQqL
You can use the local.css file for your CSS overrides
D) This is usually caused by a WYSIWYG editor (e.g CKEditor) that you may have enabled in your installation. Please make sure that the configuration of this editor does not affect the markup of these pages
E) The easiest way would be to hide it through CSS for the mobile screen widths
F) Our theme does not override the default drupal multilingual functionality. The official D7 multilingual documentation should guide you through the overall process:
If you require any further assistance or clarification we suggest that you start a private ticket (Email us option in the sidebar) so that it will be easier to share login credentials, live URLs as well as code snippets.