I suspect BB8 is named that because each of the letters and the number looks like him, and a single B8 would be too close to Forrest Data from Nemisis.
Damn. Finn. That name is among the top ten boy´s names over here since 2000 ... something with a bit more power would have been nice. Same goes for the x-wing pilot, and DEFINITELY for the dark character. A "potential" (!) antagonist with such a soft-y name. Y, L, O. Yello. KY. lo. Ren. Ren faire? Ah, well, it´s with kids, I guess, their names have to grow on you, as they grow into their names.
Maybe her last name, or first will be more unique. "Luke" is pretty bland too.