I played the demo awhile back (entirely in Japanese), and it definitely got me interested in the title. It's different, but in a good way. I'd check out some gameplay videos, and if it looks interesting to you, give it a shot. Personally, for me, this is half the reason I'm buying myself a second PSP after selling off my first a couple years back.
Not really. This is still the only portable version translation available, and Square has voiced no plans to bring the FF Type-0 HD version to the Vita, despite the fact that it was Vita fans that wanted it more than anybody else, transitioning from trying to get it over on the PSP back when it initially released. Of course, the Vita thing might change with the uproar surrounding the decision to not bring the game to Vita, but with how game companies operate, I wouldn't bet on them changing their mind.