AAQ:
1) You have it backwards. If anyone, all the more so a “Religious Zionist”, so publicly and pompously claims it is his duty as a Rabbi to go against the mesorah of our poskim going all the way back, then they are gravely profaning Hashem’s name unless they provide a valid halachic explanation for the same.
The Zionists and their weapons are not relevant, of course, as the particular weapons they do or do not have do not impact that they are enemies of Hashem, His Torah and His holy people.
2) As I wrote in my last post, the particular judges on that B”D are irrelevant. The “Chief Rabbi” specifically noted in his video that he was relying on his predecessors having done this, not on a psak from those Rabbanim.