The IAA look to have published a very practical Q&A on drones that clarifies a lot compared to the last time I looked at this.
https://www.iaa.ie/media/DRONESQuestionsandAnswersFinal1.pdf
If it weights between less than 20kg, and footage is not for commercial reasons, no licence needed. Otherwise, training course and 12 month licence.
Not within 5 miles of an aerodrome
Must be flown by line of sight, not by POV, and not higher than 120m
Not over built up areas
Not flown within 50m of people who are not being managed by the operator
Drones less than 1.5kg have more relaxed restrictions. See IAA SI25/1000
https://www.iaa.ie/index.jsp?p=100&n=107&a=406&pp=253&nn=488&lID=283
Regarding private property /privacy, the IAA have no comment on this.
What about where you fly 3' parallel to a closed line, with each landowners permission? Pretty much in the clear there, surely?
The onus is very much on the authorities here and they are still 5 years behind in implementation.