the only way you will have to take it to the dealer is if you have the active steering option. As for the lowering you should be good. I'm running -1.05 upfront and im not lowered and doing fine wear and handling wise. As far as the rear you are allowed -1.75. I would let the car settle for a few and then take it to the alignment shop. I did mine at pep boys with no issues and also took it to a tuner shop also. No difference only in price.
oem perf cf spoiler and front lip/m3strut brace/m3 subframe bushings/wavetrac lsd/ TMS solid diff bushings/MR adjustable toe arms/MR adjustable upper link/full m3 suspension/ecs tuning ss brake lines/GC coilovers./CPE dci's,catless dp,intercooler,charge pipe bov/BMS OCC/tuningtechfs tuned/RB pcv valve/defiv diff lockdownkit