Going through the steering geometry individually, the Ackerman angle would only be affected very slightly and in fact could end up being slightly better. The Ackerman angle change has more to do with the difference in wheel base between the Adventurer and Torana. The steering arms are fixed from memory to the strut. Unless you bend them it shouldn't change much. Either way the toe out on turns would be much better than the original Torana set up which was at best pathetic.
The scrub radius and king pin inclination will not be affected unless for some reason you decide to bend the stub axles, its a fixed design angle between the strut and the stub axle assembly. However a wheel offset change from the original Adventurer offset will effect the handling. Its not the width its the off set that will cause the car to handle different. But the wider the wheels the more they tend to tram track on some roads.
Caster and camber is directly related to the position you place the top strut tower mounts in. When setting the top mount positions I would try and get hold of a decent angle indicator to ensure they are both laying back the correct amounts for caster and the struts are equal both sides, and the strut angles are leaning in the desired amount for the cambers you want to achieve, Try to leave a bit of movement in the top mounts for minor wheel aligning changes when its all finished. Correct me if I'm wrong but from memory the radius rods have shim spacers at the front for minor caster adjustments.
Because your only moving the outboard components equally in by 57mm I don't see to many dramas effecting the geometry causing any major bump steer issues so long as you use the original control arm and ball joint.
Any change in steering rack inner ball centres and lower inner control arm mount positions is where the real issues start and can cause bump steer. For good handling characteristics suspension ride height is important and I think you should be mindful in this area. Lowering the suspension ride height can cause quite a bit of camber change. As previously stated its the roll centres that will be effected the most due to the modification.
I cant see any change to anti dive under braking unless you dramatically change caster. One matter to consider is the spring and shock rates. Having slightly less leverage due to the shorter arms will reduce the leverage. Probably not enough to have any major effect but should be considered.