OK, I'll take it on, reluctant as I am to start lest the rant flow unabated ...
I was on one of the early JAA ATPL groundschool courses. I then started to teach at the school, and am still a groundschool instructor.
1. Less proscriptive, more flexible licence requirements. I did in fact debate with Genghis the many people we each knew who were forced to do ridiculous amounts of a certain type of flying, although they had experience of similar but more challenging flying in slightly different conditions. For example someone I knew who was a senior officer in the Royal Navy and an instructor on EH101 Merlin helicopters, with a full career of night dunking in Seakings behind him, doing 50 hours night flying in a Cessna 150! We had both also ben in the same position (my pointless journeys in a Cessna 150 to get a free cup of coffee were vital, my navigation in a gas-turbine helicopter at 200' and my instrument time in the same aircraft were irrelevant, counted for nothing).
2. No. Very little benefit, massive problems, especially for students and Flying Training Organisatios (FTOs). Some students were forced to sit exams in a made-up language ("Euro-English") for which the syllabus had been layed down to vaguely cover the questions submitted (and did not even do that) rather than questions being written for the syllabus. The schools had no prior knowledge of what the questions would be like or the depth of knowledge required at first (JAA refused to allow accurate example questions out). All were ill-prepared becasue of this, and the notes were approved despite all being at the time completely inadequate (those still using 4-Forces notes admit their's still are, and tell students not to use them in class!). Now JAA has offered no recompense to the students so shamelessly and disgustingly used to experiment with a new, obviously unworkable system on. These people have sometimes lost a year of their lives to JAA
The syllabus approximately doubled, but no more relevant information was included - it is estimated that 90% of the required ATPL syllabus is irrelevant to a pilot. Thus you could pass all the exams with good grades and know nothing relevant. For points which could be debated (especially in the psychology side of Human Performance, where the experts disagree) the FTOs are not given the reference from which the question is written, so it is impossible for even them to find the "correct" answer.
For a long time the rules had not been written - for example I tried to convert an FAA PPL, was tld that it was allowed, but the "requirements had not been written". When I studied law there was a part of the new JAA system that we could not learn because at the time it was only written in Spanish!
The international "co-operation" problems have caused anomalies, mostly because of intransigent French and Germans. Notably the question bank in English but translated by none-native English speakers, mostly not aviaiton specialists. The CAA did offer to translate them all.
It is crazy that a CPL is now required to teach to PPL level. There was nothing wrong with the old system.
Why is there no concession for CPL holders doing the IR exams or vice versa? One of the exams is identical!
Why are there no reasonable ways for pilots with none-JAA CPLs to acquire JAA CPLs?
Why is JAA so reluctant to approve overseas training?
Why get rid of the 3-tier medical? The system worked!
3. Don't know, except that we were one of the first, so got the worst of the problems, and I know that there have been problems with the Italians accepting a UK pilot. In fact I had heard that the Italian implementation went completely wrong, but not the details.
4. No, but under the circumstances one is required. The requirements of the PPL have risen for no obvious reason.flying in the UK is no harder than it was, the NPPL is now as a colleague said to me today "back where the PPL was 30 years ago" (when he instructed)
5. Certainly not enough communication with the FTOs either way, nor the airlines as to what
they wanted ATPL students to learn in groundschool. The FTOs were not significantly consulted (except to be asked for questions, before the syllabus was even decided) nor kept well-informed.
Best of luck with the MBA. If you have any questions feel free to email, address in my profile.