FFXIV in SEA

[WOTA]

What your solution might be at the moment (since removing regional lock won't take 2 days, if they will even decide to do that at all) is to ask somebody who has access to the game in Steam to buy the expansion as a gift and send it to you or will at least find a way to send you a code you can activate in mog station. That's not a perfect solution, but it's better than nothing while you can't buy the game by yourself.

As for subscription, shouldn't Mog also have debit card option along with Steam Wallet and others? Or it doesn't accept your country cards?

We're not the first one to have requested to make the Full Game available on SEA (although I believe we're the first one to actually requested it on the official forum).
I've seen people have been asking for it to be available since a long time ago on Reddit and Steam Forum, yet there's still no words from SE which actually makes me a bit pessimistic about the whole thing.

Thanks for your suggestion, but unfortunately gifting doesn't work,
my friend has an Argentinian Steam Account and he can't gift it to me since the product isn't available in my region.

Japanese Mogstation doesn't accept my country CC, or even any other countries' as far as I can remember.
It only accepts Japanese CC.