benny you make some interesting points. As for the parrying, in the beta at one point in time we actually had parry animations. They were done by quickly tapping the block button. They even worked on what you just described, the parry-attack. In fact those parry-attack animations are still in the game files and are there as a resource. (for now?) In any case, the parry-attack was never introduced, and the parry animations were removed, no one really knows why.
As for the swing direction i can say i have experienced the exact same thing. I will sometimes fling my mouse upwards for an overhead attack but it still wont recognize and instead does the right swing. It is really annoying.