Some of these aren’t that far off from the American process. It being an ARM, not being able to get a house if you’re going to retire, and the impermanent job type are a bit weird though. Usually for Americans, you need to show some years of steady income to qualify. It doesn’t entirely matter what your job is - as much as you can show with your tax returns that you’re making steady money (for years) that can afford the home. The having kids thing is weird and I don’t get why that would be against you.
I’m guessing there are much stronger tenant rights in Ireland where they have a harder time evicting the person and making it impossible for them to find housing later. (Credit score, legal records, etc.)
The 4x income and 20% deposit is very common here too. Going past 4x would require unusual circumstances. People doing lower deposits and/or higher ratio incomes are not common especially in the major cities. You might qualify for a special loan from the VA or through FHA but it has penalties like having to pay PMI and being locked to only homes of a certain price.