Crank
No there are no compatibility issues with the larger big ring. The front derailleur may have to be moved up a touch. The bottom bracket may be the wrong length for the new crank but your shop should be able to tell you.
The headset is the bearings between the headtube and the fork steerer tube that allow the fork to rotate in the frame.
Why are you changing cranks and what's wrong with the headset?
No there are no compatibility issues with the larger big ring. The front derailleur may have to be moved up a touch. The bottom bracket may be the wrong length for the new crank but your shop should be able to tell you.
The headset is the bearings between the headtube and the fork steerer tube that allow the fork to rotate in the frame.
Why are you changing cranks and what's wrong with the headset?