This might be worth reconsidering. I'm reminded about the recent ruling regarding starting from save states. In this case, allowing the use of a modified ROM opens the door to there having been some kind of other modification that would give an unfair advantage. Of course, there's nothing stopping people from trying to do that with the original Japanese ROM, and I've seen a few speed games that allow runners to use cosmetic mods in their runs. I'd personally like to be able to run the games in English too, but I thought I should call this out early on.
Who knows, maybe it will come out at some point that the English patch also fixes a bug that changes gameplay slightly, or maybe text loads faster on that version. I'm not saying it does, just that allowing things like this opens up this sort of vulnerability in the future.
Oh lord, haha. I wouldn't be against adding it I suppose, but I'd definitely never run it simply because I loathe puzzle mode. xD Unless somebody made a tool that showed you the solutions to the puzzles and it was allowed during runs. Although even then, I don't have all that much time for speedrunning, so a 6-hour run is definitely out of the question for me haha