Can you please help confirm if the GoG version has the issues that were presemt in the Steam release (gamepad inertia/ pool minigame aiming being overly sensitive/etc fixed in this release or is it a 1:1 copy to the Steam version? (minus Steam,'s CEG obviously).

I doubt it's much different (if different at all) from the Steam release, but admittedly somebody else will have to confirm either way. This release is mainly just for those who want Steam-free copies / installers.