Axi 2208/26 not the best motor for this size and weight plane. Have to use a small prop. Might work but not the best. More appropriate for a 6 to 8 oz. plane I think.
Vibration might be caused by an unbalanced prop, which you checked, or a bent gear shaft, prop not firmly attached to prop saver or seated flat on the saver. If not tight on the saver, the prop can pull forward under power and vibrate like crazy.