Hello,

1-Please go to file includes/core/codeless_elements.php and find this line:
vc_remove_element("vc_separator");
Replace with this:
//vc_remove_element("vc_separator");

2-Yes, you can modify them, but after the no 1 fix the vc_separator will not take up that much space and there won’t be needed to reduce the font of the text. However, if you still want to change it, then just add this code into your custom css box:

.vc_gitem-post-data-source-post_title div { font-size: 14px !important;}
.vc_gitem-post-data-source-post_excerpt div p { font-size: 14px !important;}

Change the values to your wish.
Let us know.

Best regards!

Hello,

No. This file is not listed in the Edit theme list of files. You have to access it using a ftp account or cpanel. See this screenshot for details:
https://pho.to/AgEff

Best regards!