I just had my 330 aligned today at an independent all-makes shop with a nice laser alignment rack. The shop is aware of the ballast requirements for our cars but they normally guestimate the alignment specs to use without ballast. They don't do a ton of BMWs...
Anyway, when the tech set up the machine, it led him thru menus of body style, selections for standard, sport or rough road suspension, and wheel size, before it presented him with the required spec that matched my Bentley book. It also described checking ride height, recalibrating the steering angle sensor, some other calibrations, etc, that don't apply to my car, and of course, diagrammed the placement of ballast.
Happily, I provided and installed my own ballast - ten 50LB bags of concrete, wrapped in trash bags. Only $32 at Lowes.
So, to answer the above issues, any shop CAN align a BMW. Whether they choose to turn you away, or whether they will take the job and not perform it to spec, or if they do it properly, well, YMMV. I paid $90 and, with a little guidance, got the job done right.
But I do have a question of my own, regarding my Sport Package convertible, stone stock, with 125K miles. My previous tires were Toyos that lasted about 35K. They should have been replaced at least 5K sooner, as one rear tire was thru to cords on the inside. The tread on the outside was decent, and all of them were worn unevenly like this, just not quite thru to cords. I think all the tires could have gone 10K further if the car had a more tire-friendly alignment. I assumed the car had far more negative camber, especially in the rear, than specified. That would explain the tire wear, and correcting it would get me better life out of my new Continental tires. I was surprised to learn I had LESS than the specified negative camber amount. The tech brought it closer to stock, but not to the full 2-point-something degrees.
My ride height, btw, is about 0.6" lower than the spec, which allows a 0.4" deviation.
If you have a mostly stock car with stock alignment, do y'all eat up the inside edges of your tires while the rest of the tire has many miles left? I don't like throwing away $200 worth of tread when the inside edge of my tires goes bald. What will I lose by going to 1 degree negative camber, like a non-sport pack car, instead of 2?