make sure you verify the gap is correct 100% on plugs, i bought 6 new plugs from bmw and 6 from amazon (bosch oem) and all 12 were defective (gap was too little). i ended up adjusting them to the right spec and they worked after that. also new coils can be found on amazon $136(bosch oem units, not reman)
yes do the walnut blasting! also i had a lurching issue as well but this tuneup as well as MHD flash tuning to stage one solved alot of the drivability issues.