JM said:
1. "Why was Jesus not saying, "Not My will, but MY will be done?" if there is only one person and one will involved when He was praying in Luke 22:42 & Matt. 26:39."
Oneness Penetecostals (aka. "Jesus Only") and Unitarians are 2 different groups. It seems from the content of your question it is addressed to Oneness who believe that Jesus is the Father. Unitarians, in general, do not believe that Jesus is God at all.