To qualify as a magistrate do you need to resign from any boards of non profits one may be on?

There is no single answer to this question. Your own board may have by-laws that limit your working as a magistrate. Also, as a magistrate, you cannot hear cases that directly affect your personal interests. In general, you should be able to serve as a magistrate without resigning from any boards you serve on. However, if a case comes before you that involves your particular organization, or that involves an issue that could directly affect your organization, you may have to recuse yourself from that case. If this happens often, then you may need to resign from the board.