I have been able to win domination victory on deity thanks to your advices, thanks a lot!
Things that helped: having continent with Canada and Sweden helped a lot, Canada never attacked me, Sweden did but thanks to a big mountain range and only two narrow points I was able not only defend myself but also get all her cities.
One thing I noticed is, that even though Australia was very strong in all metrics, he never attacked me and when I did with jet bombers, GDRs and my navy, he wasn't able to do anything despite having 5x bigger army. So once I settled decent number of cities and survived early DoWs, it was as easy as immortal. One thing is that I played with only domination victory turned on which makes a lot of difference, if not, Australia would win science/culture way sooner (but I would attack him much sooner aswell).