I found the tips very useful.
I was however surprised to see the usage of the "all" non-standard property in a snippet (slide 183) in a presentation that teaches best practices -
var leftSide = document.body.all.lSide.value;
How does "Standardize file capitalization convention" help performance? Does a consistent file name help in the file getting cached?
w.r.t "Asynchronously Download Script using the async attribute", is the async property for the script tag available in IE10? W3Schools says the async property is "supported in all major browsers, except Internet Explorer" while the MSDN HTML/XHTML Reference doesn't mention it.