prohibition of most of its citizens to travel for tourism abroad in order to keep that money in Japan

I'm not sure about Japan, but until 1979 British tourists were not allowed to carry more than 50 pounds out of the country. While it sounds exaggerated currency restrictions was considered normal in the post-war era.

Mostly not true. The Japanese "miracle" is kind of overstated. Japan in the aftermath of WWII was left in total rubble after the US bombing campaign practically destroyed every single city in the country. The vast majority of the population was short on food, shelter, and everything else we like in. However, Japan's workforce was extremely well-educated, used to industrial labor, and demographically booming. It's kind of hard for your economy to not boom when you have engineers living in rubble. In the same manner, both Christian Democratic West Germany and State Socialist East Germany boomed (albeit West Germany did better).

A lot of analysis of the Japanese (and Chinese) economy are kinda based on domestic political concerns - usually "Japan is doing this one thing and look how miraculous they are - we need to do it too!" The clearest example of this is the Chalmers Johnson thesis, where he argued that Japan boomed because elite Japanese bureaucarts (in MITI) were able to successfully pick and choose "national winners" to compete in the global export market. He presumably wanted a lot more bureaucratic planning in America. This has generally not held up to historical scrutiny, especially because MITI actually had a pretty bad record of picking winners (they tried to stop Sony from exporting because they figured nobody in the world would want to buy Japanese radios).