So, because I was still following some workflows really dated from Youtube, Pharan guided me back to where I should be with the current workflow to initial character setup. Previously my character was using SkeletonAnimation which didn't go well with mecanim without extra script to trigger animations, but now that I've got it under SkeletonAnimator things look like how they should be.
However, I've got a problem, though.
My character's poses are mixed after their own play: like when I play idle -> walk -> idle, then some bone rotations and positions seem mixed up. They don't go back perfectly pose after pose. Can someone point out what could have gone wrong in this case?
edit : omitted the question part since I simply just figured out how to work with mecanim events. Still has no clue about how to resolve the pose-wrecking, though.