Have you even taken the time to check if there is already a thread on Irish grammar? I swear I'm the only one who checks threads before posting.
I gave you the link due to the thread getting updated over time as well as you confused me with the title and your initial post here of "Need Help with Grammar in Irish". GRAMMAR is not just An Tuiseal Ginideach (The Genitive Case), it's a lot of things.
I have not got a clue. Only reason I can think of is to get you prepared early for LC Irish as LC Irish (HL) is very difficult and you have to learn a lot of literature - so thus reducing your stress. Do you think this is why?
No, nothing like that. There is like a question or two (very small ones) in the Grammar question BUT the answer will be right in front of you if you know your grammar like séimhiú or úrú. They are like only worth 2 marks each though. So don't mind the Genitive Case until you get to Leaving Cert.