How do I plug in an emoticon into my keyboard
The feature that emoticons can appear when you type in a word was introduced in some previous Swype versions earlier, maybe with version 2.0. It is hardcoded and not subject to change in any way, like so many things concerning Swype. The only thing is that you can switch off the icon prediction, if you run a newer Swype version. If your keyboard came preinstalled, you need to deacitvate it and buy the actual Swype keyboard on Google Play.

Hardcoded also is the languages dictionary and in some languages the dictionary is very poor (e.g. german) but since long they got never updated/repaired. The only thing the user can fill is the user dictionary, which is very limited to some few hundreds entries, then it is full and older entries are deleted. Also this is not changeable.

The Swype keyboard (run by Nuance) is as it is and the support (e.g. in the forum) is nearly not existing, so don't hope about any change. 

Sorry, nothing you can do. Use it as it is.