As far as the high-lighted section goes, there was very little that was unorthodox or novel except for 3 things?
1. The Japanese use of oxygen fuel torpedoes. But they used the same torpedoes in Cruisers.
2. The use of high pressure steam in the German and American navies. But again, in each navy the use of high pressure steam was navy wide, not destroyer specific.
3. The use of high angle main guns in the American and Japanese destroyers, but again the Americans were using the same gun in every ship that was big enough.
The Japanese used a different 5in gun on their battleships and cruisers. The 'declared' DP guns used in most of the Japanese destroyers were sometimes replaced by the some 5in guns used by the Japanese on the large ships. Much like some British Tribal's replaced one twin 4.7in mount with a twin 4in mount to improve AA the Japanese replaced one twin 5in/50 mount with the twin 5in/40 mount for better AA, which should tell us all we need to know about the AA capabilities of the Japanese 5in/50 gun and mounts.
The use of specialized AA weapons or the dedication of destroyers to a single role (AS for example) came after the outbreak of the war.
Firstly the Japanese 5in/50 gun gun mountings came in a variety of types, on which the elevation varied from 40 degrees through 55 degrees to 75 degrees depending on the destroyer class and the particular mount concerned. They all however shared one factor in common - they had to be loaded at +5 to +10 degrees elevation. Accordingly their rate of fire was slow, making them ill suited for AA work. By 1944 their use seems to have been confined to providing barrage fire.
When it came to increasing the AA armament of their big Type A fleet destroyers, the after superfiring twin 5in/50 was replaced with a pair of triple 25mm (amongst the addition of many more single, twin or triple 25mm). See "Warships of the Imperial Japanese Navy 1869-1945". Friedman also notes that in his "Naval Anti-Aircraft Guns and Gunnery" book.
When the Japanese needed to produce a smaller escort destroyer for mass production from 1942, the Matsu & Tachibana classes, they were given a single 5in/40 forward and a twin aft, both types having an elevation range of -7 to +85 or90 degrees. This is Take completed in June 1944. These were the Japanese equivalent of a US Destroyer Escort. 1,260 tons standard displacement, speed 27.8 knots. As designed 24x25mm (4x3, 12x1), one quad set of TT, 36DC. MOre 25mm and DC were added as the war went into its final year.
The replacement of X 4.7in mount in the Tribals from 1940 was just part of an attempt to upgrade the AA firepower of RN destroyers generally at that point using whatever was to hand. The Tribals were lucky getting the twin 4in. Other classes sacrificed a set of TT for a 3in gun (generally the older classes up to the I class) or a single 4in Mk.V (J and later classes). The survivors in the fleet destroyer role, generally had the gun, which was pretty much useless anyway, replaced in 1944 with a set of TT again.