I think that you need to request the price increase when updating. Or at least my themes weren’t priced higher when I’ve added WC support.
When you open ThemeForest hoping to see that old badges are back:
Try like this:
<?php previous_post_link('%link', __('Older posts', 'sample-translate'), ''); next_post_link('%link', __('Newer posts', 'sample-translate'), ''); ?>
I don’t know about you guys, but my sales are down by 70% compared to November.
I’ve changed the name for one of my themes, and I can confirm that the old link will still work, so you don’t need to worry about this (there’s a number at the end of url which identifies your item regardless of it’s name).