As far as I understood, ginge is proposing something like the header files in C++, so that users could use it to have custom GUI's etsc.....(So far I have not gone throughly into the COM-scripting and cannot comment on that.) And ginge's Idea (if my undestanding is right) is acceptable. Otherwise as he said most of the users will get fed up ultimately.
But sure, many are going to share their successful scripts, and it could work for even those who are beginners. (BTW could arise many a bug reports due to conflicts in shared scripts
) So if its going to be some kind of library files (like i said above) its would be pretty easy.
But as Patchou said there will be less flexibility for scripting if you do the above. We sould also keep in mind that most users of plus are not literate in scripts.
The program could have a scripting option, with a choice for the user to install and/or enable (By default disabled)