Re: We lived in Ireland for five years
It's not wrong, but it's not necessary. When the order is so very clear (We did this, and then we did that) the past perfect doesn't add any information. Sometimes it even ends up sounding awkward.
It can have its uses. You can use it to add emphasis to how much further in the past something was.
Another post here recently complained about a passage that started with "I had asked her..." but I found it fine because it makes it clear it was done, long gone, well past.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.