They'd have to use the engine for a different game altogether so i wouldn't get your hopes up. Instead i'd just buy it as is and stop complaining
No, they wouldnt. I am not playing MLB because its a Euro sport, or Yakuza because its a Euro centric game. It would actually be a reason to buy it, since I could just buy MLB instead otherwise.
A localization would still give them money, even if it might not sell as well as in japan.
Edit: TotP recommendation sponsored by Solid Snakes behind:
First trailer for Konami's Pro Baseball Spirits 2013 is here!
It's coming to the whole PS-family, presumably the footage is PS3, but last years version was very good looking and playing on Vita.
This series doesn't get the love it deserves so i hope that MLB The Show fans watch the video and give PBS a try this year (releases March 20)!
For those concerned about language, www.spiritstranslation.com is an excellent website to see you through the games.
PS3 version - More pics on the official website