Hi There,
1.) No need to setup two wordpress sites. This will result to more work and setup. Unless you prefer it this way.
Each stack on X theme has it’s own design for portfolio and blog page. Now if you don’t want the default blog design available for your current stack, yes, you can customize template using a child theme. Depending on the extent of customization, if it’s not too far on the current design, it might be possible with just using custom CSS and not redoing the entire blog template.
This basic guide will be based on the integrity stack using the integrity light child theme.
See this if you don’t have a child theme yet.
Find the file in wp-index.php or wp-single.php (depending on which you need). They are found in these paths:
/wp-content/themes/x/framework/views/integrity/wp-index.php
/wp-content/themes/x/framework/views/integrity/wp-single.php
Note: If you are not using integrity stack you can find similar files in the other stacks’ folders.
Make a copy of this file and paste it in the exact path but within your child theme.
/wp-content/themes/x-child/framework/views/integrity/wp-index.php
/wp-content/themes/x-child/framework/views/integrity/wp-single.php
Those files are for blog index and the single post template.
If you need to edit sidebars, featured images and post meta etc. you will need the corresponding files found in the same folder and possibly also some found in the global folder.
content.php
content-video.php
content-quote.php
content-portfolio.php
content-image.php
content-link.php
content-gallery.php
content-audio.php
content-page.php
/global/_content.php
2.) For each license, you are entitled to use it to one production site only and one development site.
Hope this helps.