[porker]

I can answer all except "What's the difference between display: inline-block and float: left?". What is it?

I learned CSS when IE6 was new and shiny. I think there's a gap in the market for books to update skills - e.g. a "What's usable in CSS since IE6?". I still find odd things I can now use as I only have to target IE8+...

[just2n]

If you want to learn more about this, the visual formatting model in the CSS 2.1 spec is very readable: http://www.w3.org/TR/CSS2/visuren.html.

If I were interviewing a candidate, I wouldn't expect them to be able to deeply recall most of that detail (though I'd expect them to be familiar with the basics). I'd accept an acknowledgement that floating an element takes it out of the flow, while using inline-block doesn't, as well as some further detail about what that means, what impacts/side effects it has on other elements and markup.