Balk Question

[Xtopher_66]

Obviously the balk is one of the toughest calls in baseball.

My basic understanding is the following:

The pitcher, while in contact with the rubber, can only do 3 things legally:

a) deliver the ball to the batter

b) step and throw to a base (or feint toward 2nd or 3rd)

c) disengage the rubber by stepping backward with the pivot foot (thereby becoming an infielder and can pretty much do anything at that point)

Let's assume right handed pitcher, runner on first.
Now, my question has to do with the step and throw to a base part.

Can the pitcher after coming to a set position lift his right heel up and spin on the toe of the right foot, step with left foot towards first and throw to first? All of this being done quickly and smoothly.

Does the right foot also need to move closer towards first base during the throwing motion or could the right foot remain in front of the rubber?