Cleon
Legend
None of the above, since it has racial HD. It would fall into the "add/subtract from 10 for even scores, 11 for odd scores" method. See the bugbear or gnoll for an example. That's what's great about monsters with racial HD...making 'em playable characters is an afterthought, and less work.
Thus, its scores are Str +2, Dex +2, Int +4, Wis +4, Cha -2.
Favored class rogue is fine.
Erm, it is one of the above then, namely the third one "completely average (11, 11, 11, 10, 10, 10)", or near enough for government work.

I did like the idea of giving regular kobalts the non-elite array but am OK making them bog standard stat arrays.