I'd say all of these problems are solvable. But at what cost?
It would probably be a better solution to make it possible to run RTG graphics directly on the Indivision, circumventing the AGA chipset. That would be cleaner and faster, especially for those of us with fast accelerators.
(I have no idea about how the Indivision gets data from the CPU or memory directly, though. Perhaps there are significant limitations here as well. But certainly there will be enough bandwidth for smooth mouse pointer movement. )
As thing are now, I'll live with the mouse pointer issues. In interlace the mouse pointer wasn't great either, and at least in 30p scrolling of text and graphics looks a lot better.