Nice analysis, @pavithirakc
It's up to you what's next.
You could complete ploneorg.addonlisting so that we can get it onto plone.org - I think that would be a nice feather in your cap, to be able to point to something you helped write that the main Plone community site is using in production. However, on its own it may not be a very demanding project; it will require attention to detail and some design work, if I recall correctly (@Alexander_Loechel can provide more direction).
If you can come up with a solution to the stats problem, that would be nice for the community as well. But again, is that a GSoC-worthy project? It's less about coding than it is about human problem solving, if we go with the "human action is required, even periodically" approach.
Or you could plan on trying to use some "no human intervention required" approach, which probably shouldn't rely on pypi statistics, but should rely on some sort of (optional?) reporting (periodic or maybe one-time) from each Plone deployment.
To answer your questions:
ZMI Python scripting means going into a Plone site's Management Interface, e.g. http://localhost:8080/Plone/manage_main and adding a "Script (Python)". These use Restricted Python so imports and other possibly harmful things are not allowed; however they probably can do what @djay suggests.
That's something you'd have to propose