@mikawagunichi
1 is easy enough.
2 this could be done but I don’t know how to do it.
3 is easy enough.
4 could be done but pretty sure all repairs would be done then. So Factories and Harbors too.
5 I don’t think this is possible, maybe there is a work around. You’d probably want to eliminate convoying and do it manually with edit.
6 can’t be done. You’d have to hand roll the extra bombard and the bombard hit by hand before battle and use edit to apply the result. also before battle.
7 This is possible but would require a fair amount of work.
Anyway, I’d suggest contacting the creators of the original map and see if they’re interested and even though triplea is open source, it’d be courteous to ask for their approval to make a mod if they’re not interested.
All that being said, it’d be more than i would want take on. Although I’d be happy to help with any questions if you decide to take it on. You might also ask at the triplea site https://forums.triplea-game.org/ in case anyone is interested in taking on a new project.
Good Luck