The only things I can think of are to check to see if the qube is short on memory (e.g. free -h or top from a terminal) or CPU (e.g. top or uptime in a terminal).
Might want to make the min/max memory the same in the qube settings so you can be sure you know how much is actually allocated to the qube.
The other thing that comes to mind is that it could possibly be a video card driver issue since you specifically mentioned scrolling. I have an AMD card and don’t have much experience installing in dom0, but I see there’s a post about how to do so for nVidia cards.
Hopefully this will help you figure out where the problem lies and gets you headed on figuring out how to fix it.
Side note: Wowee! 96GB of RAM in a laptop is very impressive!