Re: the anchoring-the-pinky issue while using a pick:

It may be a good plan for certain styles of picking, such as playing melody - as it stabilizes your hand and allows you to maintain a better sense of orientation to the strings.

But for rhythmic strumming, the achor-pinky is going to take away from the power of using your hand, wrist, and arm to play a rhythm. It's likely to make the rhythm feel constricted, held-back.

Maybe best to get used to both techniques, so you can choose as appropriate to what you want to play.

Hope this helps a little!

-Lisa