A simple unique program ID would solve importability. Load event sheet / ini, check ID against internal ID.
And although this COULD be used for patching, I'm really thinking more of a level editor thing. Like Smash Bros Brawl, where users can use existing objects with a small choice of backgrounds and place them how they please. Or in my case, much the same with a little more flexibility within my own custom encounter scripting. No objects or textures need be added.
After all, you're right about patching tools. And yes you're right that python is better for mods... but I'm aiming for the end user, not the master modder. Construct event structure is far easier to understand and incorporate into an existing project.