Thanks so much for the detailed response, but actually GOG got back to me and the answer for the mouse was much simpler.
It's just the text size. Both my monitor and TV are 4k so I have the text size set to 200%. If I manually set it to 100% and run the game the mouse icon shows up fine.
But still does not allow me to play the game as I need a controller! I guess I misinterpreted posts about it, but GOG nicely offered to issue a refund, which I have requested. Hopefully they will add controller support so I can re-buy and play the game.
- John
