The horse glitch, I have no idea how it exactly occurs, but I feel that I do something similar most times it happens and can't pinpoint what. I made a topic a long time ago hoping that something with WSE2 could address it, but to no avail.
The old 1h right swing, it just felt very awkward. You just swung and turned and hoped it hit first. It was so slow, that I could spam 1hs that tried to right swing after a block in most scenarios. It only needed a slight tweak, and now it works great imo. My bias against it came from both using it and taking advantage of others who used it. It was only useful in a few cases: backpedal swinging after a block, and switching from it to another attack direction. As an approach, overhead seemed much more useful and less likely to get blocked.
After a while, I completely replaced it in my playstyle with overheads and only noticed improvements. The looking down thing sounds interesting, but then wouldn't that worsen your range? Does the enemy have to be at a specific angle on your right, or can they be in front of you? Does it work against decent armor, or does it have to be a lightly armored opponent so you can hit that early? I usually look downwards when I fight, but have only seen my right swing hit absurdly early only once: on a lightly armored foe that was trying to hiltslash me, and it was only enough damage to stun him.
Now, I feel there is good balance between all four attack directions. Left swing is indirectly weaker since right swing can outreach it more easily, and one would need better positioning against someone using the longer overhead or stab, too. It remains great against the other classes, but left swing spammers can get outpaced by more clever 1h players.