K, I'll start this, let's keep this nice and neat. I would use the
Feature - What it does
Inspector Icon In Tool Bar - Allows you to set the level which you want
the inspector to operate. You can turn off inspections, and ask for
code validation only, and turn everything off completely so you can work
quickly and then check your code to see if everything is OK.
JSP Code completion - This works with dynamic imports too now. You can
get code completion for you CSS, HTML and many custom tags, and IDEA
understands the semantics of those custom tags as well.
JSP Surround with - Highlight some line of text, surround with and you
get a tag mark which allows you to surround your code with the tag of