CCAF was obtained through military skills credit.
I did not receive the American Opportunity Credit while earning the 64 credits.
Yes, as long as you meet the other requirements.
If you are a qualified student, going to a qualified educational institution and you haven't claimed the American Opportunity Tax Credit 4 times already you may claim the credit for tax year 2016.
It does not matter how you earned your credits up until this point, as long as you are not paying for your 2016 expenses, used towards the credit, with tax-free assistance.