I knew eventually you would see life from my point of view.

On the flip side of your example, your grandson also has the option to not ask you for your advise. He gets the toy that he originally wanted, no more aware of the "better" deal then before but perfectly happy with his decision. He still has an intimate relationship with you, he has not done Your will, but because you created the rules that he could make his own decisions and you would honor them, then to keep the intimate relationship you accept his choices and celebrate his choice of toys and his decision. Your Will states that you will accept and bless the decision of the grandson.
Maybe the discussion on the Will should go back to number 1. Once the Gift of Free Will and the consequences of having Free Will was given, you also bound yourself to accepting the decisions caused by that Free Will. God's Will and Love is in the acceptance and use of the Gift to humankind. When we do not use the Gift of Free Will then we are in opposition to God's Will.
Maybe that is why it is important to know and do the Will of the Father instead of what we believe to be right for us (as Jesus taught). I will have to half agree with you on this. It is the knowing of what is the Will of the Father that is in question. As Jesus asks on Gethsemane,
Yet not as I will, but as you will. Is he talking about the original desire of the Father noted in Genesis? For man to become as "one of us"? In which case, Man would emulate the all encompassing Love of God that is given to everything. To have the power to 'create" a pure and sinless world - "eden" again. At that moment in Jesus' life, he notes that his soul is despair as if to death. A biblical analogy of depression. He can at this point choose to run away, save himself, not complete his task. But he is looking to the Father for assurance, advice and confirmation that his choice will be right one for humankind. It is telling that the Father does not answer him, but allows Jesus to make his own decision based on Free Will. We think that the decision to die is the Will of the Father, but it is not stated in the bible or in any of the Gospels that the Father answered Jesus and told him that to die was the Will of the Father, that I know of. Jesus chose his pathway, the suffering, the crucifixion from a point of Free Will. Which the Father accepted as being His Will.
I did like your analogy about the grandson.

Like he really asks you for advise on a toy.