accidentallyc I guess I did not fully understand your second question. Writing plugins is not that complicated, especially if you were to write a plugin just for your game, for private use.
Assuming you want some custom javascript code executing every game tick, your plugin could have just one C2 "action" defined in the edittime.js and then have that action be called from C2's every tick event. The runtime.js would be as complicated as you wanted to be. If it you just need a few lines of code then the JS function that gets called when the action is fired would have only a few lines of code. That code can access any C2 object instances and their behaviors and properties.
If you want some custom code to be called when a certain event is fired, then instead of having your plugin action called on every tick, just call it when the the event is fired.
Another way of "text editing" the C2 events is to open the event sheet files in a good text editor, but that is definitely not a supported (or good?) way of doing things and you have to be very careful (make backups!).