Fine groves in the rotors are not a big issue; they will not affect performance or cause vibrations.
When you take the car in have the mechanic measure the rotor runout. It takes 5 minutes. BMW recommends replacing rotors when there is more than 0.2mm of runout.
Straight lines are for fast cars...turns are for fast drivers
'04 M3 - track
'06 650i Cab - daily driver
'02 Highlander - kid hauler
'01 330Ci - winter beater