im no expert on tires and wheels here but from my understanding is the E34 requires a 40 series tire if u run an 18. If your tires are too tall then yes, they will rub when you turn.
also i wouldnt mix springs and shocks on a car. you cant use gas and hydralic shocks on the same car.
Im actually in the process of putting new bilsteins and eibachs on my car and finishing up tommorow. Im pretty excited to feel the result and when income tax return comes ill be getting some 17 inch ASA AR1s for her. If you want to talk about blown out shocks i should show u the fronts i took off. the drivers side one is so bad it wouldnt even rebound once i pushed it into the housing. hmm, probly the reaso why the car wanted to go to the left whenever i hit a bump hard. but i already have the fronts together and the rear ones assembled. now all i gotta do is bolt em in and R&R the rear ones and im ready to roll.