Okay, if anyone else is STILL having this problem (which I was even after trying every single fix on here) I have found a way around it using the QWERTY keyboard on the Galaxy Note2:
1. In the messaging app
Right after I type the word I want as a shortcut (no spaces or anything after, with the cursor on the right edge of the word)
2. I pull down the notification bar and go into settings. (The gear on the top right)
3. I scroll down and go into "Language and input"
4. Click on the settings (gear to the right) of "Samsung Keyboard"
There's an option that says "Continuous Input" with a checkbox next to it.
5. Uncheck the box, then recheck it. (Or check and uncheck, whichever you prefer. It works both ways. You really only have to hit the button once.)
6. Click the home button at the bottom of your phone.
7. Click back into your "Messaging" app and the shortcut will magically have appeared in the shortcut/suggestion predictive text box thingy.
(If it doesn't work after the last step, try only hitting the checkbox once in step 5. Sometimes tapping it twice screws it up)
Hope this helps! It took me hours to figure out!
