I agree with most of your points except this:
>>Moving divs around, adjusting CSS or erasing pencil off a piece of paper is never going to be as efficient as clicking on a layer and moving, resizing it, etc.
As a visual designer and front-end developer (that knows Photoshop very well), code is actually far more efficient for modern UI's. It's much better organized than the PS layer model, CSS gives you tremendous reach with your changes (especially with SASS/LESS), and Developer Tools (or Firebug) give you amazing reactivity.
However, that being said, the designer must have both design skills and coding skills, which aren't, and shouldn't both be a requirement for the position. The most creative and best graphic designers tend to not know code well enough to become more efficient with it than their traditional layout tools.
The best middle ground for "thinking for UI" and quality graphic design is Sketch. Sketch eliminates 80% of the stuff you never use in PS for web design and adds the features you didn't know you wanted. Its styling options reflect the styling options of CSS. I can't recommend it highly enough.
Honestly, unless you have some very complex personnel issues, every web designer should be using Sketch over Photoshop (and maybe use Photoshop for image manipulation).