Hi there,
1. How I remove the additional css, we compose the post from you composer, and not put any additional css.
Actually, css/styling mentioned above are coming from the template and Easyblog them itself. We striped them all and it is not necessary to implement them on Print view.
2. When print pdf, we want to remove some elements from the post such as: author, category, ... is it possible.
You can edit them here
.../components/com_easyblog/themes/wireframe/blogs/entry/default.print.php by removing codes below. Please give it a try and see how it goes.
<span class="post-category">
<?php echo JText::sprintf('COM_EASYBLOG_POSTED_BY_AUTHOR', $post->getAuthorPermalink(), $post->getAuthorName()); ?>
<?php echo JText::sprintf('COM_EASYBLOG_IN', $post->category->getPermalink(), $this->escape($post->category->getTitle())); ?>
</span>
3. I want to add header and footer to the pdf file, is it possible, this pdf file look like catalog or brochure pdf.
You should be able to customize this files
.../components/com_easyblog/themes/wireframe/blogs/entry/default.print.php as well and add them respectively.
To avoid those changes from being overwritten on your next version update, you need to do template override for that files as you can refer here
https://stackideas.com/docs/easyblog/administrators/customizations/template-overriding
Please give it a try and see how it goes.