They answer (partially) in the faq: https://www.cia.gov/library/publications/resources/the-world-factbook/docs/faqs.html
What is The World Factbook’s source for a specific subject field?
The Factbook staff uses many different sources to publish what we judge are the most reliable and consistent data for any particular category. Space ...
This does not resolve the conflict, but traces its origin.
One of the first links that appears from your Google query is for
Internet Live Stats that also presents the 84.2% number and what seems to be a justification by giving the total population and the number of internet users. That source cites "Elaboration of data by International Telecommunication ...
It might take quite a few queries, but all trade data should be available here: https://comtrade.un.org/data/
You can select up to 5 countries (either as reporter or as partner) to view their trade with all other countries (select all in the other box). So in about 50 queries you should be done. There's also a bulk download option which I haven't tried.
I have just checked the OECD's Statistics database, and I find the following GDP figures for France:
The output approach figures from the OECD match those of the INSEE and Eurostat.
The figures that you attribute to the World Bank correspond to the figures that the OECD obtains by using the income and expenditure approaches. The three approaches are ...
I'm surprised by the question since each and every one of the indexes you cite (GNP, HDI, HPI) have extensive documentation on their calculations that are generalizable to any global data source whether that be the UN, OECD, World Bank, whatever. Look them up on Wikipedia, find their analogue inputs in the WDI list and plug and chug. It would take only a few ...
You can pull the metadata directly from this URL (xml returned by default):
It looks like it has what you need. Regions/groups are treated like countries but you can distinguish them based on empty or "NA" field values.