When one has sex, one must be prepared to accept that a baby might result. Sex and babies go together. They were designed to go together. Sex was not intended as a “stand-alone” pleasure. If one is not able to accept a child right now, then one does not have sex right now. NFP allows women to know more about their bodies, in order to know more about their own fertility. It does not change the fact that no babies = no sex, even if only for a few days out of the month.
Now, about the declaration of nullity, yes, you would have to accept either decision. It is not something that the Church “does” to your marriage. It is the Church’s investigation into whether or not you were validly married to begin with. It is like a doctor getting tests back from the lab. “I don’t want to send in my biopsy samples because I will have to accept the verdict of benign or cancerous.” Whether you send in the samples or not has nothing to do with the actual truth. You were either validly married or you were not. Just because of things you have done afterward (attempted to contract a second marriage), it does not have any bearing on what you did at the time of your first wedding.
As for authority, you do not quite seem to understand or accept the whole concept of a teaching authority. The Church is the Church which Christ founded. In Scripture, which the Church upholds and has never discounted the validity of, Jesus promised St. Peter that He would found His Church upon Peter and that the gates of Hell would not prevail against it. In Scripture, too, we are told to accept the traditions we had received. In this modern age of writing, we can too easily discount oral tradition, but the Church, which stretches back to Christ Himself, kept the Traditions and wrote them down, too, eventually.
What do you think is right about the Church? Why do you want to be part of it?
I do not wish to sound harsh, but these two issues (artificial contraception and the inability to remarry if one is validly married) appear to be two issues in which you have a vested interest. Your examination of these issues should, to be fair and accurate, take into account your bias against these teachings. Would you be having such difficulty with the Church’s exercise of Her authority if you did not have a vested interest in Her being wrong?