A: I am not sure that I understand your question fully...but I will answer with some ideas that may be helpful to you.
Accepting any source as "the" authority on the will of God runs counter to the teachings in The Urantia Book—especially the teachings of Jesus. While The Urantia Book is a marvelous revelation, and a sure guide as to the value of seeking and finding God's will, it is not, and does not claim to be, an "authority," and any attempt to capture those teachings and create a religion of authority out of them means to me that you maybe need to read and study further.
There is only one authority when it comes God's will, and that is the authority that comes through your inner experience with God, who dwells within your mind as the Adjuster, and who helps to "adjust" your thinking to correspond with God's will. When we make the decision that declares "It is my will do do your will," we are then on the right track. The decision to do God's will does not include rebellion against that will. Although that is certainly a possibility, it is never a good choice, as can be easily seen from our planet's unfortunate history...for example, the default of Adam and Eve, and the Lucifer rebellion.
There is no force that can go against your freewill decision. It is solely yours to make. Likewise, it is solely your decision to reject the leadings of your Adjuster, if that is what you want. I have no way of knowing what your future decisions may be, but I suspect you do not want that...
The Urantia Book is a revelation—it is a sort of roadmap that helps us to see the big picture—to discover our place in the universe, our place in God's family, our origins and destiny as human beings. Your acceptance of the teachings should not bring fear of losing your freewill. God himself will not interfere with your free will.
Rebellion against God's will is now, and has always been, a matter of individual choice. In the same way, choosing to do God's will is also a personal choice; freewill choices are made in the mind, and expressed in action. They may be influenced by outside factors, but free will choices are not pre-ordained according to outside factors. The responsibility for each choice lies with each individual.
Adopting and living the teachings of The Urantia Book should help, not hinder, the living of a life dedicated to the seeking and finding of God's will. If you continue to sincerely study and explore The Urantia Book, you will easily see that your fears are totally unfounded.
For more information on these topics, please see our study on God's Will HERE, and also our study on Free Will HERE . It also may be helpful for you to understand better the nature of Revelation, including the revelation that is The Urantia Book
I hope this answer has been helpful to you...if I have not addressed your question fully, please write back with more information."