1. you may or may not need a turndown, every car is different, however I have the s2 kit and I need it
2. use the egr block off for the evap on the blower, not the PCV
3. the zzp bracket will be the best route
4. yes, you will need the 99+ alt bracket and alt. Also, you will have to address the coil pack bracket to allow for belt clearance