“1) Japan and Israel have different maritime needs: The Soryu is a huge boat, weighing over twice the size of the Israeli Dolphins and with almost twice the crew. The Israelis will be hard-pressed to find/train enough personnel for it given the allocations for their navy.”
Crew size is not related to capability of a submarine. The standard crew size of a Type 212/214 submarine is 27 men. Israeli Navy did add additional crew men for additional weapons. The crew size is related to axiomatization and reliability. Search for Collins-class crew size...
Did you ever thought about the range issue for Japan? The Soryus are big but what about range and endurance?
“2) For all the Germans say, they have subsidized the Dolphins they built for Israel to varying degrees. Will Japan do the same?”
Germany didn’t subsidized the Dolphins. It was a political redemption for German companies supporting Iraq with missile technique. The price for a Dolphin class submarine is about $500 million without the special weapons. BTW for the last Dolphin class submarine Israel paid the full price and still is thinking about another one.
I would prefer a fleet of Type 210mod: https://www.thyssenkrupp-marinesystems.com/en/hdw-class-210mod.html
Crew size DOES matter a great deal. No amount of automation can override the need for manual backup. Which is why the Royal Navy and USN still have close to or over 100 men on their subs.
You talk about the Collins class-well, the Australian navy did increase their complement to 58 (about 15-16 more personnel) to cope with engineering issues:
http://www.asiapacificdefencereporter.com/articles/301/SEA-1000-CREW-SIZE-UNDER-PRESSURE
The ‘standard’ complement as advertised by manufacturers is rarely the number a navy will put on them. South Korea seems to have about 40 personnel on its Type-214s, which is nearly 50% more than the ‘standard’.
http://english.yonhapnews.co.kr/n_feature/2013/08/02/57/4901000000AEN20130802008900315F.HTML
The Soryus have an optimum balance of range and endurance-the Type-214 has a endurance over two months if it were only on AIP, which would mean very low speed. When you need to run at higher speeds, you’ll need to use your D/E mode and the Japanese have the larger fuel capacity for this, in addition to the Sterling AIP.
The Israelis say their Dolphins were funded by the Germans-so whom do we believe? Companies can’t pay ‘redemption’ money to foreign nations without political clearance.