I think, civil liability-wise, any liability from a magazine safety removal can never arise unless something bad happened that would not have happened had the mag safety been untouched. This means no access (with or without your permission!) for dummies or kids, at home, range or anywhere, until the gun is put back to original. For example, someone could steal it, get drunk & shoot their buddy with it by mistake while the mag was out and said buddy could file against you. Or, what if said thief picked up the gun (without mag inserted) and shot someone on purpose? He couldn't have done it if the mag safety worked.
Anyone:
Specifically, is it against any law to remove a mag safety here?