I asgree with you. All things are present before God. The future past and present God can see them all.
We're in an area none of us comprehend, in my humble opinion. I have trouble with the idea that God can predict my future behavior because He knows me so well. If I am predictable, then it's not possible for me to change my behavior from what I have done in the past. At least this poses a logical problem to my little brain.
On the other hand, what if God does not predict the future? What if He just sees it, as we see the present. There is a big difference between PREDICTING what we will do and OBSERVING what we are NOW doing in the future, as if it were present. This solves my logical problem of predictability, but it opens up another unfathomable concept, that God lives in the future as much as He does the present. That's also impossible to comprehend.
Elder Holland's last conference address says:
"These various evolutions and iterations of creedsand others to come over the centuriesdeclared the Father, Son, and Holy Ghost to be abstract, absolute, transcendent, immanent, consubstantial, coeternal, and unknowable, without body, parts, or passions and dwelling outside space and time."
Is Elder Holland stating that it's a false doctrine to believe that God lives "outside space and time"? Usually when people say that the past, present, and future are all before God at the same time, it's because He lives outside of time.
These type of philosophical or logical questions rattle around in my head from time to time, but I can only speculate and then realize that I probably have no capacity to understand such questions of eternity. I take comfort in knowing that God is "all knowing" of the past, present, and future, and yet I have agency to choose as I will. I can become something I have never been in the past, something better, if I will it to be and put forth the effort.