Hello Lee,
I have not driven a Passat but moving from a "sporty" 3dr Xsara to the 6, you notice that the suspension is firmer. The Citroen felt like it was a softer car, like the chassis was soft and "bending". The other thing you notice is that the 6 has short travel in the suspension. The 17 inch tyres do not have a huge profile as well. There is a good chance that the Passat is close to the Citroen set up because of its European background.
Having said that, you should not need to fight the steering wheel to go straight. It is sensitive based on how bad the road surface is but you should never need to fight it for too long. Maybe it will give you some unexpected steer but it stops there. It is more a sensation that you get because it is electric. As you are not the first owner, you do not really know the history of the car.
It could be something simple like poor maintenance and never done any alignment. So that is something that you could check. It is a service item but not really done. If there is any work done to the car, then the alignment could be wrong. Or if the car is parked on pavements and other strange places.
The cheapest inspection is to check the tyre pressures. These go from 32psi to 38psi depending on how loaded the car is. The more air you add to the tyres, the more responsive it becomes but not always in a bad way. The firmer tyre will follow less the bad road surface and so it will come out better than the softer tyre that will follow the road more acurately.
If you have a problem like a broken spring, it would show up more often I think. I do not think that you need to replace the springs and the shocks but maybe you need to do the tyre pressures and the alignment. If everything in the suspension is there, e.g. no broken anti roll bar links, then the car should drive the same in good and bad surfaces.
It is not uncommon for these cars to need a new steering rack. But when it comes to that, you experience bad steering most of the time.
I would keep the car empty from any unnecessary cargo, add air to the tyres and if you do not feel safe with the car, go for an inspection. Something like that should easily come up on the MOT. If the garage cannot find any problem, there is a chance that what you call fight, is the normal electric streering set up combined with the particular road surface.