JP vs ENG

Hello,

I'm curious on the actual cards used in various parts of the world in official tournaments;
0) All of SEA must use EN or JP? *like Philippines, Singapore, etc*
1) I know there is a separate format between EN and JP, but what if a store does not distribute JP cards, can they still "host" a separate format for JP only?
2) How to determine that a distributor can actually host "official" tournaments. Is there a ranking system already?
3) Will there hopefully be a change in this system? There are several people who are disappointed and can't really play using the JP cards they have because of this rule where only EN cards can be used. Or at least have a system where players can trade in their JP to EN and vice-versa.

Thank you.