My thoughts below:
- Elastic-band acceleration (Tip-in)
Try performing Transmission Adaptation as per this thread:
http://f30.bimmerpost.com/forums/sho....php?t=1182679
- Suspension
Depending on your budget, I think coilovers would be a better fit for your needs, as it would change the dynamics much more than lowering springs. Check out KW Street comforts or Bilstein PSS10 (or KW V1)
- Brakes
Sounds like a pad change might help with your issue. I know the Euro BMWs get a different pad than NA.... maybe try using the NA one, which is supposed to be more street and less performance oriented (or go with aftermarket pad like Hawk or EBS).
Personally, I have no issues with my brakes, I like them quite a bit. I agree the suspension is a bit soft, but I actually like that, as it rides better on shitty roads (I daily commute with my car and do about 90% city driving). If I was upgrading my suspension though, I would probably spend the extra and go for full coilover setup over just lowering springs (or shockware for that matter)