Dusty Crop,
Firstly, I don't really have any more views on what you expressed in your post, but would like to point out that the final report on this crash did answer the questions you pose regarding the ATC and flight plan issues. I believe everything is pretty well explained and covered in the conclusions and findings on page 32/33 of the report. Not that this makes what happened any more acceptable by the way, the fact does remain that the families had to raise the alarm the next day (I do accept that there were contributory factors to this also, and that the report does state that apparently the accident was not survivable, which I hope is of some comfort to the families of the deceased).
Regarding the filing of flight plans for (presumably) VFR flights in Ireland, I always just file over the phone to Shannon and have never had a problem so far, but thats just in my limited experience.
Finally, to Colm and Dermot, Ar dheis Dé go raibh a n-anam.