If the game takes place before Black and White, it would be better for Keldeo to appear on its own, as opposed to having it and the Masqueteer Trio reuniting before the event at the Moor of Icirrus. Also, this choise of placement in the timeline would make Genesect have a logical appearence too -- an N and Team Plasma event related to Genesect, probably as a DLC in a later date. Probably not, however...
When it comes to the starter, I wouldn't mind Zorua, but I'd prefer it if there were more choises, probably. Still, there aren't many things you could place Zorua along with. Minccino is quite similar to Pikachu and Marril, which is why I want to see it being used as a starter Pokémon at some point. But I don't particularly like Cinccino, so, I would probably prefer it as being used by another main character, much like Lyra had Marril. There are also the elemental monkeys, which would also work for Triple Battles, but I'm not a big fan... I suppose Zorua fits the bill best.
When it comes to the starter, I wouldn't mind Zorua, but I'd prefer it if there were more choises, probably. Still, there aren't many things you could place Zorua along with. Minccino is quite similar to Pikachu and Marril, which is why I want to see it being used as a starter Pokémon at some point. But I don't particularly like Cinccino, so, I would probably prefer it as being used by another main character, much like Lyra had Marril. There are also the elemental monkeys, which would also work for Triple Battles, but I'm not a big fan... I suppose Zorua fits the bill best.