Very handy list.
One gripe I have is with n°7. If you set the text to auto instead of fixed, you’re not taking into account that this specific text can change (and it always does — that’s why Craft is quite handy as you can import real data).
When set to fixed, the margins will remain correct on either side and the text will have the maximum length you asked for, just in case. As a front-end dev too, nothing is more annoying that a button floating next to a title that just wasn’t “supposed” to be that short.
I design with auto for most of my text areas, but set them to fixed once happy with the result and willing to export.