Should someone get their CPA license after graduation or work then go back to school?

Also my school only offer Masters of Accountancy in taxation. If I get a Masters in Taxiation does that lock me into that type of job forever or can I get a Masters in Taxiation then eventally expand my knowledge base to include skills like auditing. Also if I had a Masters in Taxiation but knew how to audit am I going to be able to do it or would my superiors just say no you went to school for taxiation and that is what you do.