Am I the only one who noticed the skinjob's similarity to the Zoe skinjob at the end of Caprica? I'm betting it's an evolution of whatever she was or what became of her. Obviously skinjobs like her either never became convincing enough to pass as human, or more likely they never saw major usage to a point at which their existence was common knowledge.
As for the Cython, I look at it this way. It's a war show, most likely taking place way more on the soil (or snow, or whatever) of the Twelve Colonies. We saw no full on ground warfare in BSG aside from skirmishes. It seems that B&C is gonna be more of a war show than BSG was; imagine a show all about war that only has 3 types of enemies. Gotta have some variety in there, right??
Granted, I think it'll be interesting to see how they make cool looking **** that (hopefully) spans the gap between U87's and the RDM Centurions without making the Model 0005's and old school Raiders not look obsolete and out of place.
But let's be honest, it's BSG and we're gonna watch it regardless.