So after wondering why I only have 2 character slots, I did some research and found out that you have to upgrade/validate/whatever your account in order for your account to be treated as full and get additional slots.

Although that doesn't really bother me, since 2 chars are more than enough for me in this game, I'm now rather curious how to upgrade your account at all.
And who knows, maybe the additional slots will coem in handy one day.

So, how does it work exactly? Is it even possible for one that doesn't live in Taiwan etc?

Thanks in advance.

I would like to know this aswell.

IIRC it's outdated - every account is already full. You can't get more than 2 slots, unfortunately. You can always just open another account, though.