Loop item customization through child theme

Hello!
I’m using GDF theme for WPGD 2.0062, and made a child theme to leave all core plugin & theme files intact and updatable.
Right now I need to tamper with loop that outputs listings on a category and location pages. More specifically, I need to change some meta-data (for example output some custom fields data) in loop items, and add a filtering option that would output featured listings first but sort them randomly. Is there a way to do that without getting my code under the plugin’s hood? Right now I’m considering writing my own set of functions for child theme and replacing the_content() with my custom query, but if there is an easier way to do it through some WPGD features still unknown to me, I’d be happy.
Thanks!