Hello Marcel,
Thank you for your post. It seems like you are well prepared for your trip next week and did a lot of research already!
The information, which you found on the website is correct, yes. Assuming that you are EU citizens, your national identity card is sufficient to travel throughout the island of Ireland (including Northern Ireland), as long as you are arriving and exiting the island via an airport or ferry port in the Republic of Ireland. In short that means if you fly in and out via Dublin your national identity card is all you need to travel the
entire island.
Only if you would be travelling direct to/from Northern Ireland or travelling on to Great Britain from Northern Ireland, you would need a passport. Please also bear in mind that this information is only valid if you are EU citizens. This information is also reconfirmed once more on the
visas and passport page.
Thank you also for your suggestion on the updates on the website. I will pass this on so that the page can be reviewed and a link or more information might be added for more clarity.
By the way, is this your first time visiting the Island of Ireland? Which places besides Dublin are you planning to visit?
Have a wonderful day,
Sarah