Including CMB2 in Theme Mood and Changing Textdomain Name of its own

Hi There,
I have used CMB2 in my WordPress Theme in theme mood.
For this, I have made a file custom-functions.php and placed it in inc folder of the theme folder. And included it writing the following function in functions.php.
In this file I have registered the metaboxes using the functions copied from example-functions.php of the cmb2 plugin which has been placed in the ‘lib’ folder of the theme. From this folder, I have included the init.php file to the custom-functions.php.
And now my queries are:

  1. Is it allowed to include custom metabox plugin like cmb2 in theme mood?

  2. If yes, is it required to change the textdomain name of the plugin itself (in this case, cmb2) with my theme textdomain (like, truelove) ?
    The code snippet of the plugin is:

    $cmb_demo = new_cmb2_box( array(
    ‘id’ => $prefix . ‘metabox’,
    ‘title’ => esc_html__( ‘Test Metabox’, ‘cmb2’ ),
    ‘object_types’ => array( ‘post’, ), // Post type
    ) );

  3. If I use any plugin in plugin mood, do I need to change the text domain with my one?
    N.B. This theme is getting ready for ThemeForest submission.

Thanks in Advance.