Managed to install and launch this fine, but at the main menu, I have no mouse cursor - waving the mouse around doesn't reveal it anywhere on screen, and consequently I can't actually launch the game itself. Anything I could try here ? Runing this on a 64-bit WIn10 system with a GTX1070 & G-Sync monitor.

What is your screen refresh rate? If it's higher than 60, have you tried lowering it to 60? (Maybe disabling G-Sync too?)

I'd have to check; monitor is capable of up to 165Hz, but I never pay attention to it in Windows. Will try switching off G-Sync too, although flipping between on and off will be irritating.

Help! I can't pan the camera with the keyboard arrows in the game view. I can only move the camera freely in the sensor map.

The main in-game camera in Homeworld / Cataclysm / Emergence doesn't have free panning, it always follows a ship or group of ships.

You can change what the camera follows by either holding 'Alt' and left-clicking another ship (or group by dragging out a selection box), or by selecting a ship then pressing the middle mouse button.
The sensor manager can be used to change focus to a ship outside of the normal camera's draw distance.

Switched off G-sync. Still can't use the mouse on the main menu, or consequently change any options or get into the game.

Thanks