Personal preference, I prefer the extra few mms at the wide end vs having more zoom. Much more useful when using the camera indoors.
12mp will have more noise than 8mp, and you really won't notice much difference unless you're blowing up to poster size. The one advantage with 12mp is that you can crop an image smaller and still retain detail vs lower mp. But if you can frame for the shoot, then this shouldn't be a big issue either.