Hey there. Couple of questions

It's very likely it will be localized by XSEED; it's a franchise that's seemingly done well for them, it's gotten some pretty good exposure, it wouldn't be a huge project in terms of script length and Tom's a huge Ys IV fan so if they haven't already picked the game up and just haven't announced it yet, I'm sure he's pushing for it.

As for how the game would be released, XSEED only knows but it's probably a safe bet that the only physical release would be in North America. Since the Vita is region-free you can import a copy when it comes out but other than that, you'll probably need a PSN account (I know, they made it harder to do multiple regional accounts than they needed to with the Vita). For Seven, you'll need either a US or EU PSN account to play the game in English on a Vita. Probably safer to make a US account if you also want to play Celceta via digital download rather than importing.

Now, I'll admit that I have no idea how easy or difficult it is to pay for items purchased from those accounts from Australia, might be easier than my experience of paying for Japanese PSN purchases from outside Japan but I can't imagine it would be harder.

You need an email address you can actually access but you don't need to use your primary one. Just make a new gmail account or whatever your free provider of choice is. Fake credit cards though? No. I'm not sure whether the US and EU services accept non-US/EU credit cards (I know the Japanese store doesn't accept US cards) but you can always purchase point cards (for whichever store you want to set up an account for) separately and then use those to make PSN purchases.