I agree with the "close all windows" button.
I keep pressing Escape, and I am repeatedly annoyed that I need to press it again to close the other window I have open.
If I have my character screen open and my inventory open, Escape should close both of them.
If I wanted to close one of them, I would press the appropriate key to toggle it back off.

A skip all dialog button, on the other hand, seems like a bad idea.
I could easily see someone skipping a cutscene or an important story bit by accident.
That would very quickly ruin a bit of the game for me, I like playing to experience the story.