How difficult would it be, though, for Google to hide some advanced options in settings for power users to enable? Always Expand Header, Always Expand Collapsed Content, etc.

When you're handling more than one or two emails in succession, every keyboard-shortcut that became a triple-click-drag adds up and takes time.

I don't believe the author is an extreme minority - Google should cater to all of its customers - requesting that Google add a few options to enable power user mode isn't unreasonable in the slightest.