For the feet, open the keyframe sheet and look at the animation curves of the feets' parameters. The default spline interpolation can cause unwanted inter/extrapolation of animation, so you probably want to switch one or the other keyframe to linear or break spline mode. About the hair calculations, the follwing things can accelerate the process: * reduce the number of verts per hair * reduce the total number of hairs * switch off collision detection wherever possible * uncheck "show polulated"