I would also like to answer. YES and I have also found that it's still productive to have been using the PSR. But...
I disagree with this as a blanket statement. It is often true, but sometimes you just know your characters better than your players. In such cases, it can be easy to choose a Concern that looks too much like it's relative match in the Domain's dynamic pair, e.g., The Past vs Memory.
(Personally, I'm blind to the OS in most stories. To me, the story is about the MC or the RS, which is why it's a pain to find a movie that I know I'm going to like. Most ads show the OS.)
On the other hand,
This is absolutely true. Plus, even if you have the storyform wrong, writing to the PSR can help make you think about your characters more objectively in different situations, giving you a wealth of material to draw from. So, yes, it's productive, though it can feel counterproductive at times.
Absolutely. I'm still working on this, too, though I'm finding Table-Top Roleplaying Games are helping with this.