1. Yes you will rub. The offset of those rear wheels is too aggressive to run 255's. A 235 can work but 225 is the best size to prevent ruibbing.
2. Your front tires are too tall/too large of a diameter. It should be a 225/35/19, not 225/40/19.
3. Just my opinion, but a more aggressive fitment such as OEM m3 wheels needs a drop in order to look proper.
GL with the wheels.