Why can’t we perform CONFIG 1+F Takeoff in the following conditions as per the MEL?
First of all SFCC1 regulates the engines idle, lo or hi, according to the Flaps/slats configuration, for instance to provide low idle at initial descent

Also SFCC1 uses the blue hydraulic circuit for Slats, in hydraulic emergency case, only blue might be available as being generated by the RAT
  therefore SFCC1 fault is a no go, SO I assume at takeoff SFCC1 is available

SFCC1 uses primary ADIRU1 so if ADIRU1 is also faulty we go into a no go condition

Now if ADIRU2 is faulty, SFCC1 should rely on a single airspeed data, therefore if the speed is incorrect premature automatic retraction of the flaps might occur at takeoff, that is going from 1+F to 1 automatically, so take off with configuration 1+F is prohibited with these faults at takeoff