Legal and Illegal Shifts

[Mike246]

Is a player allowed to shift more than once before the ball is snapped?
If so, must he pause for one second"

Flanker Z goes in motion parallel to LOS (and remains in motion at the snap.)
Simultaneously a running back shifts to the wing and pauses a full second.
Is there anything wrong with this?

Also, what are the rules regarding interior lineman shifting?


Thank you.