Also, one ton of explosives per shot was not very much when allied heavy bombers could deliver at least 5 to 10 tons per plane and in 1944 thousand bomber raids were common for both the US AND Royal Air Forces. A missile needs a force multiplier like a nuke to make them more threatening with the guidance technology available in WW2, and Germany was not even close to being able to build a nuke, and the V2 could not carry it anyway. It's direct descendent, the US Army Redstone, could, but it did not go into service until the mid 1950's.
Hitler would have been better served by using what went into the V-2 program building heavy bombers or tanks.
Germany just didn't have the manpower and materiel for a sustained war no matter how good their tanks or other weaponry. And even though Germany introduced heavy tanks and jet planes, the Allies were coming up with their own. And again, they could produce a lot more.
The only chance Hitler had would have been for his super weapons, mainly the V-2 rocket, to destroy the Allies. And again, they weren't powerful enough (no nuclear warhead), and he didn't have enough of them.