You can keep the pages, but currently page filter by category or by page parent is not possible. But i think we should go for it. Please give us this week. We will update our plugin to work with page parents filters.
Regarding modifying Lhotse theme it can be done. Here are the instructions for you.
1. Goto to Layout Themes under WP Masonry from admin.
2. From list of layout themes, Click on Copy to WordPress Theme. This makes a clone of your layout theme in your wordpress’s theme. (This need to be done to make sure this layout changes remain same even after our plugin has been updated.)
3. Once the theme has been copied, you will get a new path as notification. Which looks like this wp-content/themes/YOUR_WORDPRESS_THEME/masonry-layout/lhotse. Please open layout.php from above mention folder. You need FTP to do this.
4. In line 10, change code there to <a href=”<?php the_permalink(); ?>”><?php the_excerpt(); ?></a>. Save it and you are done now.
Hope this helps.