I cant pull up the video right now for some reason. But I will bite on the questions you asked.
Many players have some stride that leads to open postion. This is for many reasons. Some use that open stance at toe touch to help open the hips. Some like that so they can pull more pitches. No matter what your reason, you would need to have the back foot closer to the plate. If not you leave yourself open or no coverage on the outside pitch. If your to close you leave your self open for the inside pitch and cant keep it in play.
A stide to 1st base if your right handed batter cuts off really the pull pitch to the inside and only leaves you oppisite field pwr.
When you see batter with arms extended you have to first look at location of the pitch and count on the batter. Most of the time the extention your talking about is adjustment on the pitch to make good solid contact on a missed time swing.
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