This is a really, really simple tool. I made it for personal use first, but I might as well share it here so it lives on. This excel sheet allows you to set up your current WDM char, and compare the raw damage difference from different items. If you enjoy min-maxing, this tool is for you. Feel free to try it out.
This basically solves the question of "Should I get EWD, flat damage, dex/str or deadly strike?"
There won't be a "spell" version for this unfortunately. Each spell has unique synergies and scaling, which is extremely difficult to maintain and provide an "all-in-one" solution. Good luck.