If you give us the error we might be able to help
Looking forward to your video for speedup slowdown, it's important for AMD guys because they claimed they could not reproduce.
To do so you need to add a bone say hand_L and add another bone parented to it called prop_hand_L If you don't do the parenting you won't be able to animate the prop bone, as it inherits everything from its parent
The slowdown/speedup bug has nothing to do with graphics
If that doesn't annoy you sure you can continue playing that way
I'm curious what is the left panel in the last screenshot from