To your question of successful mixed marriages, here's my two cents, for all they are worth.
I have converted to Orthodoxy in early 2007, and my wife - even though technically a cradle Orthodox, - is an agnostic. To her, my prayers at home, my icon corner, my fasting, my insistence on going to Divine Liturgies are absolutely weird. She does not understand me. She has completely different philosophical, religious convictions. But she loves me, and we, therefore, have no real problems. She thinks I am cuckoo, but she loves this cuckoo and she is ready to make some sacrifices for this cuckoo's sake.
All other members of my extended family (my mother, my daughter, my son-in-law and his parents and siblings, and my mother-in-law and sister-in-law and two nieces), and all the numerous friends of my family, and all of my own friends from the times of me being a university student and later, - all of them are pretty much like my wife. But, again, they love me and therefore the difference in our religious beliefs is not a problem.
So, from the side of agnostics and atheists (my daughter, of all the above-listed people, is more of a serious, angry, militant atheist than an agnostic) there is no problem.
How will it be for you, what reaction you will have as a non-Orthodox from the side of those who are really Orthodox - I do not know and cannot forsee. But generally, I know, I know very well, I know with every cell and molecule and fiber of my soul, that mixed marriages, mixed religious convictions in a family can be something that is not at all harmful to you.