I'm not the best at troubleshooting Macs. Simply because it doesn't come up much. They do one thing very well, they work!
Remove any third party hardware, do a fresh install, and get all the updates after install. If it still freezes with every piece of hardware and software 100% factory, take it back and make them fix it right. Macs should always work out of the box because all drivers and software are designed for their particular hardware.... So make sure you're not running any third party drivers that operate at ring 0.