2) Ok, i think its worth working on this for the future !

3) Well, pot file available for the translation (the one which can be downloaded with the theme ), does not include related posts translation. However, i went into plugin editor into

designthemes-core-features/shortcodes/shortcodes.php 

and was able to alter the text there manually.

4 ) Can i somehow change the style of the “related post” section?:

https://prnt.sc/gk6u9p