Hi and welcome to the Forum .....and before anyone else asks - PICTURES PLEASE
Runflat tyres (RFTs) - do a search and you will find loads on here with the consensus - change to non RFTs with a significant improvement in handling.
Bak discs - if they are in poor condition get thm changed now. Certainly not worth the risk running on dodgy discs - get the pads changed at the same time of course.
Welcome to the forum. Sounds like you've maybe got "sticky steering" - if you Google it, there's a good load of information and potential fixes out there
Welcome - I was in Holmfirth earlier today ate tea at Piccolinos ! Was in Mrs Badgers Audi not my Z which is also a 2004 2.5 yes I agree the roads are great fun !!