Unlikely. If it happens only when you move your arm, it is unlikely to be a tia. It may be related to irritation of a nerve that supplies the arm. This can be sorted out with a careful neurological exam.
No. Clearly this is a functional problem in that it doesn't occur unless you lift up your arm. It would more likely be pinching of a nerve in the clavicle area or perhaps vascular from blood flow in the arm.