Hmm, in my MS Word (Word X for Mac), [CMD =] toggles subscript, and [CMD +] a.k.a. [CMD Shift =] toggles superscript. Don't know ways to zoom document in Word other than the Zoom seletion in the View menu or the zoom percentage value pulldown menu in the toolbar.
The [CMD +] in the browser, Safari, etc. just zooms up the fonts. The same command in other apps may have different functions. In iTunes, for example, [CMD + or -} raises and lowers the audio level.
The OS X Universal Access Zoom control [OPT CMD = or -} makes use of Quartz Extreme to provide a very high degree of magnification with impressively low degradation.
If your scriptwriting app doesn't support the greater document enlargement you need, try changing your screen settings in System Prefs>Display to something different just for your writing sessions - if you're at 1900 X (x) change to 1600 or 1344 or 1280 to get a "larger" image.
You also may want to experiment with the font "smoothing" settings in System Prefs>Appearance,, especially with an LCD monitor.
Myself, I've got those "arm's length, up close" glasses for computer work. They make a huge difference.
Thanks, you are right about the MS Word zoom function. I have it set permanently at 250% and it works perfectly for me. As does command-+ to increase font size in my browser or command shift + in my email program. I can