Madferit,
your Bug Reports :
weird anim
(3rd one)
I couldn't notice anything special.
racquet did a weird "double" swing prior to impact
You were running forward and the game anticipated the impact based on that, then you pressed your strike button, and thus slowed down, and so the game adapted its prediction.
character did a 360 before hitting that forehand
There was a little rounding error to check on what side the ball was, leading to that issue. It's fixed for the next update, thanks to your report !

character tried to hit a volley way later
I cannot notice it ; on the last volley, where your player cannot reach the ball, and his hit time is exactly when the ball is on his level...

character does a fh when I was trying to hit a backhand
Once again, you were positioned to do a FH...

I think part of the issue is the inverted forehand animation gets activated too quickly. Here I might've misjudged a bit I admit, but the inverted forehand anim gets activated basically as the ball is crossing the net, not giving me any time to adjust manually to my own imprecision, if there's even one on the first place. Cause it feels like the animation is literally pushing me into overunning the ball xd. I think the anim unnecessarily "chooses" the shot for you and it does it too early at that. It limits movement rather than make it more fluid.
If you're positioned to hit a FH, it's normal your player is starting to do a FH ; it's be much more problematic if he didn't.
The animation isn't doing anything ; it's always you who control your player, except if you press a strike button, or if you start to run in the opposite direction of the ball, and then release left/right ; but it doesn't apply here.
my character does a weird stutter prior to impact.
When the player was changing his mind about turning to run, the IK was changed completely instantly, leading to this weird behavior. It's also fixed for the next update, thanks to your report !

character in black does a weird ainm after hitting shot.
I'm not sure what you mean here. Right before your last strike, you move a bit, which leads to switching from a forehand to a volley forehand, so the preparation stutters a bit, but it's expected with such a kind of change.