I highly recommend using 2 priests.
I've said this many, many times over, you can't DPS when you are dead. Sure, having 2 priests lowers your DPS, however it lets you survive so you can DPS. There are many mobs in this xpac, that you will not be doing without 2 priests, unless you have full hardmode raid gear from DoV.
Second option is better gear.. PQ's are a great way to get some basics, just take 1 or 2 toons (don't be a retard and take a full group on auto follow) and farm them every hour.