I honestly think a lot of the fine points of hitting are very difficult to distinguish without being able to go into slow motion. However, I think one area I would focus on was getting a distinct separation between the shoulders and hips. They are rotating in one motion, rather than the hips opening while the shoulders/hands stay back and create torque. As far as your original question about the front foot, without being able to judge what the original video looked like, in general I'd say who cares (presuming it isn't outrageous) as the open foot is seen in multitudes of MLB hitters, and enables the hips to come through easier than a closed foot (and, honestly, I know the arguments for a closed front foot (keep shoulder closed?) but I just don't think they are very related; maybe someone has a further opinion about this?).