Great work with this! I spent some time playing the hack today along with the new translations of 2 and 3. It feels so good to have them all in great shape now.
Just a couple things I came across so far that I wanted to ask about or point out as feedback. I haven't played the original localization too much and some of these issues may be with that version but hey, I figure this is the perfect opportunity to address them.
1. You mentioned being french and the possibility of issues with the English. Overall what I read was really good. The only thing that jumped out at me so far is that you have "sushis" on the menu when in English we use the word "sushi" for both singular and plural. All my french speaking friends say sushis in English so I know this is a common thing but it probably should be changed.
2. With the dice mini game in the first town, you have the text say "less than 10 is low", "greater than 11 is high". But with that phrasing, 10 wouldn't count as low and 11 wouldn't count as high. I've tested it and confirmed that betting high and getting 11 is a win for instance. It should be changed to something like "10 or lower is low", "11 or greater is high". That verbiage would include both numbers.
3. The line when you travel to the second island "When something's wrong with Edo, action must be taken" sounds awkward. "Something's wrong with Edo and action must be taken" is perhaps what you were going for?
4. When training for the jutsus, the trainer has you doing push-ups while saying "fight fight!" repeatedly. Doesn't make sense. Maybe something like "harder, harder!"? If you need a quality Japanese translation I could get you one.