Nicolaus,
I've just filled in your survey, hope it is of use to you.
I know it's not quite what you mean, but I'd suggest that the biggest obstacles to the implementation of FDM are cost and legislation!
1) Make it cheaper/subsidised. FDM is just a very specific form of safety data. Other more general forms of raw safety data have become free over the years e.g. the AIP (under most but sadly not all national aviation regulators) or weather data. Why should FDM be any different? There is even an argument that if the state just paid for the kit and installation, it would make the money back several times over taxing the revenue of the businesses that provide the analysis...
2) If you can't stomach business getting freebies, then legislate! Why have an arbitrary 27.5T limit in Europe? If there must be a limit then make it the usual 5.7T, or simply mandate it for all a/c (operating public transport or not) which have at least a couple of Data Acquisition Units. I bet it wouldn't be hard to demonstrate on an individual operator or even fleet basis, the safety benefits. No, not the number of crashes! But the number of lead indicators, classic examples being the number of reported unstable approaches, long landings and poorly flown missed approaches.
The technology is getting cheaper all the time and there are more suppliers than ever. Under the risk management principles of As Low As Reasonably Practicable that we're all supposed to live by these days, this is a no-brainer for everyone concerned.
What pilots and a/c operators do with the data once they get it, though... I guess that's where your survey comes in, Nicolaus! It has been my experience that, contrary to the received wisdom, it is line pilots who learn to be positive about FDM before their management do. And as for Compulsory Disclosure...
Good Luck with your research
the Wings