Is one capable of seeing what they choose to see

If your earlier comments about Rev have any relevance, the answer would seem to be “yes”.

BTW, in the above quote, your use of grammatical number is interesting; does it reflect your personal belief about the integration of the individual with the “whole”?

is what one sees inclusive to the experience of the potential within all that is, or exclusive to personal belief?

If personal belief is to be divorced from the “experience of the potential within”, then you have answered your own question about the individual’s potential for selective observation.

If one can choose, is choice limited or infinite in possibility?

Any limitation would necessarily be imposed by our 4-dimensional perception of reality. A lot depends on whether or not you regard the scope of choice as realisable within our finite perception or as a potential that might require some preternatural support for its realisation.

Can one know God or simply see what they want to see, and if one can know God could they recognize when someone is simply following a belief or immersed in a constant that is beyond individual belief but also within the belief system?

Any attempt to answer this question without first undertaking a rigorous definition of the terms used would simply be to walk into potential mire of convoluted word games. For example, you would need to define:
a. God
b. knowledge of God
c. belief, as distinct from knowledge
d. what you mean by “a constant that is beyond individual belief”
e. how something “that is beyond individual belief” can be “within the belief system”.

The exigencies of family life prevent further contributions at this point, but I will try to respond to your other points later.
There never was nothing.