Re: 300 meter blast radius
I think this was a development version and in no way a 'production' piece.
The smallest bomb you can make is about 200 tonnes TNT equivalent - that what just banging a couple of sub-critical hemispheres together. To get bigger blasts you start adding a lot of weight - in 1957 I'd guess the missile that carried this also vibrated like shit and so for a demo to scare the ruskies you would produce a small light but more importantly reliable warhead that proves the point. Adding clever explosives and special detonators required to make a bigger bang would simply have been too unreliable,
This version would never have been used in actual combat - as you point out 300m is pretty useless as that's 2 second of flight for a slooooow bomber.
What you really need is Tsar Bomba - that would have cleared the skies for miles, or as Chocolate Starfish Prime showed you could use one to knock most planes out of the sky in a thousand mile radius,
Biting the hand that feeds IT
