Hi, I've been working with Enhanced Animations for about 6 months now.
1. I assume by source you mean the loaded model from which you are "Extracting" the animation from? If so then no it doesn't need to be in the source once extracted. In fact the idea is that the extracted animation be applied to a model with no animations of it's own built into it.
That's a big part of Enhanced Animations. Rather than loading all the animations for all models built into the models themselves, many of which (people) can have the exact same animations, instead animation-less versions of the models are loaded. The animations are loaded and stored separately from the models, and linked/unlinked to one or more models on the fly. It makes things load a lot quicker.
2. You are correct. oacID is just a variable meant to store a number. The number is important because its used to reference that objects animation controller. The number is usually different than the object number, probably for efficiency. You will need that number use most of the animation commands with that object.
