TL;DR Replace your init script with this one. It uses sudo to change to the RabbitMQ user before starting, stopping, and checking the status.

Here's a link that corroborates what I found: http://www.mentby.com/Group/rabbitmq-discuss/issues-on-rhel-62-with-rabbitmq-282.html

We're doing an upgrade of RabbitMQ here at Weebly. Moving from a CentOS 5 single node to CentOS 6 with DRBD and Pacemaker. Going from RabbitMQ 2.old-and-busted to 2.8.new-hotness. How hard could it be? Well a few things.