Your questions
Reactions to vagal nerve stimulation can be extremely variable from one patient to the next. Furthermore, it can take a few months, if not more, before being fully efficient. In any case, Vagal Nerve Simulation (VNS) does not allow patients to be cured of epilepsy, but instead it decreases the number of seizures, their length and their intensity, as well as bettering recovery. Likewise, VNS cannot replace medication. In some patients, however, if the reaction to the VNS is positive, medical treatment can be reduced.
You should avoid security gates. At the airport, you need to show a VNS Therapy ID to security agents. MRIs are possible under certain conditions. It should be discussed with your physician.
The surgery does leave scars, but the scarring process is different for each patient. It is important to adhere to the scarring instructions in order to encourage it.