The RMA is simply the return process. The 30 day window means that after 30 days, Newegg won't do anything for you. Instead, you'll have to work through the manufacturer.
Most people here don't really pay attention to the reviews. Most user reviewers shouldn't be trusted with a pointy stick, much less expensive computer hardware. The majority of complaints have nothing to do with the actual product, and if they do, the errors are most likely due to the user.