How to remove powered by

Hi,
You can add custom footer content replacing this line in footer.php

<?php do_action( 'brand_site_info' ); ?>

with your custom content.
Use a child theme or your changes will be lost with the next theme update.
Anyway, we have added a filter to change footer content. It will be in the next theme update. From that time you can use a filter to change footer content:

function my_custom_text() {
	echo 'My new site info';
}
add_filter( 'brand_footer_text', 'my_custom_text' );

hi,
should i add this line <?php do_action( 'brand_site_info' ); ?> in parent them footer.php or child theme function.php

What other controls – e.g. the individual font/size/color adjustments – over the footer ad would I get in the paid version of your theme? Can I get rid of that footer ad completely (so it won’t appear back after the next theme update) in the paid version of the Brand theme? Please let me know. Thanks.

You can add custom footer content using a filter inside functions.php:

function my_custom_text() {
	echo 'My new site info';
}
add_filter( 'brand_footer_text', 'my_custom_text' );

In the premium version you can add footer content (even html and shortcodes) visually, inside the Customizer.