I explored the Microsoft Input Method Editor options today, searching for a way to assign key commands to the various writing styles. I basically wanted a way to switch from hiragana, katakana, and regular English without having to use my mouse. After scouring the Japanese-language dialogs for awhile, essentially clicking around and reading what little I could, I discovered the proper area:
From there it wasn’t too hard to find the functions I needed and assign them key commands. I made CTRL-8 switch to katakana, CTRL-9 switch to hiragana, and CTRL-0 turn off the IME. (This is different from the standard Alt-Shift, which switches input locales.)
While I was in there I also found a way to make the IME toolbar “chisai”, so I did that too. It’s really not all that smaller, but at least now it doesn’t overlap any part of a webpage in IE.