He IS Muslim - Proof
I won't bother with all the other evidence and offer this.
He has facial hair, requisite for Muslims.
Notice how the facial hair around his mouth is just a shade more prevelant.
He shaves all other areas to the skin and clicks the razor up a notch for the 'beard'.
I've noticed this since he took office.
Also, you will be hard pressed to find photos of him eating during Ramadan.