Where I sit, names tend not to be used in court, so for example, if the Presiding Justice (PJ) has a question for the Legal Advisor in open court, they will address them as Mr/Madam Legal Advisor. Similarly, court officials will refer to us as 'worships' or 'your worships'. Aside from my visibility on the bench, I feel quite anonymous.
Of the (usually) three magistrates on a case, only the PJ speaks, and this includes making the pronouncements. If a case has wider interest, it might be reported in the press, and the PJ might be named as part of the reporting. For example, my court has a stretch of motorway that is catnip for speeders, and there has been the occasional premier league footballer in court; this is the sort of thing that can be picked up and reported on, but of course, this is quite rare. I imagine that areas with an active local press, but little in the way of news might have more court reporting than, say, larger towns and cities.
I should mention there is no expectation that magistrates will become presiding justices, it's absolutely up the individual whether or not to pursue this.
I take your point about security, but so far, I've not felt any concerns. Also, I don't use social media much, but regardless, would never reveal myself as a magistrate on facebook, twitter or whatever.