I'd really like to see you merge this TL with the "Zeppelin President" one. Butterfly away Nazi Germany and this gives you a lot of flexibility to really change the 1940-2000 period to the advantage of the rigid airship. Combine the changed political situation in Germany with with general technological advances you have suggested and the following ideas can be pursued with much fewer problems:
(1) Continued collaboration between the USA and Germany through the Goodyear-Zeppelin partnership leads to the accelerated development and "perfection" of the zeppelin airship as the most widely accepted mode of long-range air travel. As you have already proposed, development of commercial airships proceed at a more rapid pace, and no wartime haitus in the 1940's would certainly help. As was a distinct possibility in the 1930's, the USA passes legislation granting "flag carrier" status to the Goodyear-Zeppelin airlines for international travel, redirecting most US commercial airplane development away from long-range multi-engine lanplanes and floatplanes to DC-2 type craft serving domestic lines and making connections to airship docks. Extending this further into the geopolitical realm, the aviation collaboration between the USA and a rejuvenated and relatively democratic German Republic leads to the development of a "special relationship" between the US and Germany (this is not that far fetched, considering that US attitudes toward Weimar were always significantly more positive in the early postwar period than that of Britian and France). While not a formal alliance (this would be impossible due to US interwar isolationism), these changes set the stage for a radically different US posture if and when European crises develop over the inevitable German desires for border revisions regarding the Saar, Rhineland, Sudentenland, and polish corridor, as well as eventual German remilitarization (policies that would be supported by any German government). As in OTL, Weimar Germany also works secretely with the USSR to circumvent certain aspects of Versailles - and in this TL, this extends to exchanges of airship technology to the Russians, who seek to develop their own airship lines using German technology. British aviation, which is left out of the US-German collaboration, focuses on large flying boats for BOAC service within the commonwealth. So essentially by the mid 1940's, there are two largely unrelated international airline systems: (1) A German-American system of airship lines serving an overland route connecting Germany with the far east via the Soviet Union - perhaps also including Aeroflot as an operator; a transatlantic service between Germany and several airdocks in the eastern US; a joint US-German triangular service connecting Germany, the Eastern US, and several sities in Central and South America; and a US-operated line serving Hawaii, Manila, Japan, and the French and Durch Indies; (2) A British airline system based on Short flying boats and landplanes connecting Britain with Canada, India, South Africa, Australia, New Zealand, perhaps Japan, China, and other colonies.
(2) Continued US development of naval airships, leading to the existence in 1941-42 of effective long range airship scouting and ASW fleets based in both the atlantic and pacific (you've already done a good job discussing this). It is reasonable to presume that a conflict between Japan and the US might still occur. It would be fun to speculate that a force of 10-15 or so long range ZRS or ZRCV type airships hased in Hawaii might make the Japanese reconsider a Pearl Harbor strike - or make it more difficult to acheive surprise. Either way, this would change the scope and duration of any potential Pacific War. In my TL, I speculated that, with fewer PoDs, a USN airship program might continue into the 1960's - and that was with WW2 as in OTL. In this TL, the same could occur.
Questions to consider:
(1) How might this affect the development of long-range strategic bombing? It is reasonable to assume that Britain and/or France would continue to develop such a force, but in this changed TL, the US Army might not.
(2) It would be nice to have airships merged with nuclear power - extending their survival potential into the 1970's, but a more peaceful 20th century might delay this technology a lot.
(3) A peaceful 20th century might also delay the development of jet engines. That is critical, because it is only with jet engines and the vast inmprovement in speed and ceiling they provided that really allowed airplanes to become more reliable than airships and provide high-speed long-range travel that made up for their lack of amenities.