The question deals moreso in whether the pitcher is required to take a "rocker step" as part of his delivery to the plate, and whether he is required to "join hands" and "windup" in his motion.
We know in Fed that is not true.
Fed specifically states:
During delivery, he may lift his non-pivot foot in a step forward, or in a step backward and a step forward, but he shall not otherwise lift either foot.
They specifically allow delivery with only a step forward to the plate. No rocker step is required.
Additionally, you'll not find
any requirement stating that his hands must join in the windup position.
OTH, OBR states:
He shall not raise either foot from the ground, except that in his actual delivery of the ball to the batter, he may take one step backward, and one step forward with his free foot.
Now, while they state "he may", does that mean
he must?
I don't think so, and neither does J/R.
I've not found the question specifically addressed by other sources.
J/R states:
[Windup Mode]
B. Terminal Stage (Motion to Pitch)
In the motion to pitch, the pitcher's free foot
(a) may (but not must) step once backward, and
(b) must step once forward.
Neither step may be lateral (toward first or third base).
Since the pitcher
must take one step forward and is not required to take a step backward, then the "rocker step" is not required. It would be interpreted the same as Fed. Still, he must legally step to where he is throwing (delivering the pitch).
J/R also adds:
The position of the hands may be apart or joined. Joining the hands is not required before the motion to pitch, nor does joining the hands after taking the position necessarily mean the pitcher has begun his motion to pitch.
Based on J/R (the only AO I found to specifically address these questions), neither action of the pitcher posed in the original question would be a balk.
Additionally, there is nothing that says the pitcher must use the same motion for each pitch. Hastening his motion to the plate should not be considered illegal provided he has met all other pitching requirements. Still, the batter must be ready when the pitch is delivered or a quick pitch could be called.
Both are legal pitches.
Just my opinion,
Freix