Can both eldest child in the family get married?

If they are a match and they want to get married I say go for it!

Yes, they can as long they are mot blood related, example; cousins or family related. Different surname would be better to avoid anything happen to their future children.

Yes, they can do, but their effects will be the same like him/her would be the first in their family, often we think the relationship won't be that good, if it is elder vs younger will suit better etc. , thats what we had been doing it so far, may be we don't want to take risk in marrying like you said, it seems.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.