Change offset from ET39 to ET35

Hello,

My Corsa D currently has 185/70/14 x5.5 , ET39.

I'm planning to change them and put new 205/50/16 x7.5 ET35.

Please help me with the following questions:

1) Will there be any problems changing the offset from 39 to 35?

2) Will there be any problems changing rims width from 5.5 to 7.5?

3) If I change to 205/50/16 x7.5 ET35, will I be able to also lower the car using eibach pro-kit (30mm) ? or it will rub?

Thanks