My answer to your main question, that of Supernatural Faith, is that it is a gift, and as such, it really depends on God. However, we can dispose ourselves to it, and the best way to do that is to develop a vibrant prayer life, and to consistently increase the amount of sanctifying grace in our souls by living a Sacramental life.
Now, Faith is a gift which gives your intellect the *ability *to assent to revealed truth. We learn about revelation so as to know what to assent to, but we can’t truly assent to it without Faith. Some people may have an opinion that something like the Trinity is true, but yet they can actually lack Supernatural Faith in it.
As to your question about Genesis and Exodus.
Frankly, a lot of people hear bits and pieces from the scholarly community about things like this, and then presume they can have an opinion on it that is informed. IMHO, scholarly nuances like this should be reserved to scholars who have proper training to really analyze the question. The rest of us basically pick a scholar and choose to agree with him. This can be more or less ad hoc. It can also be a matter of not seeing the forest for the trees.
My humble suggestion, therefore, would be to keep an open mind, and to first and foremost work on the most important thing: which is becoming a Catholic and being able to live a Sacramental life. As you progress, you can choose to study scholarly questions about the Bible in greater depth, but I think it is unwise to think you should answer these questions before pursuing becoming Catholic.
While we should always be open to using our intellect and to learning things, we should also learn to discern knowledge that is purely theoretical from that which is practical, and we should be more willing to know practical things than theoretical ones, especially if this is called for by our state in life. Desperately wanting to know things beyond our state in life, for pure reasons of curiosity, can be an imperfection or even a sin.