When I start to scroll, Word X goes all glacial on me. Any ideas?
This sounds like the notorious problem of Live Word Count consuming every spare processor cycle. Try turning off this feature: choose Word » Preferences, click the View tab, uncheck the Live Word Count box, and click the OK button.
If that doesn't help, choose Word » Preferences again, click the General tab, uncheck the "WYSIWYG font and style menus" box, and click the OK button. This makes Word display the Font menu and the Style menu using system fonts rather than the actual fonts. It doesn't sound like much, but if your Mac has a ton of fonts installed, it can make a noticeable performance difference.
Still no good? Choose Word » Preferences a third time, click the Spelling and Grammar tab, and clear both the "Check spelling as you type" box and the "Check grammar as you type" box. Both of these options chew up more processor cycles than they deserve.
Reinstall Updaters When Necessary
I'm a good citizen, and I've been keeping Office updated. But Word keeps asking me to reapply the Office updaters I've already applied.
Relax, this is normal. You'll need to reapply updaters if you install or reinstall any Office component or if you install options from the Value Pack. Use the Help » Check for Updates command to keep Word updated with minimal effort on your part.