Improving the sequence

I experimented a bit more with the IK influence, and found by dropping the values (arms and hands) to 0.545 they seemed to sit away from the body more realistically. Full influence makes the bone lie across the empty, and with lower influence it means the bone moves away from the bone.

I realised that one of the feet did not follow the right path, it was as if it had flipped backwards.

I tried rotating the bone but this would affect it in the whole animation. I used keyframes but these had no effect, as I would have to edit it in the NLA editor but using this would force blender to crash as there was too much data for the computer to handle.

I removed any limit rotations and cleared rotation for all of the lower half.

This corrected the walking problem, but while looking closely at the feet, the right foot spins round when the body crouches down, it converts back, but I cannot do anything about it using the constraints I've used so far.

Overall though the movement is good.