Does “creating something from nothing” count as a possible action? I’ve seen arguments saying that such a thing is impossible (usually regarding the Big Bang Theory), yet the Christian God is supposedly able to do this impossible action anyway.

Your proof against God being all-knowing makes two assumptions: 1) that God is material, and 2) that there must be a 1-to-1 correspondence between each piece of information and a unit of space for storing that information. Neither of these is necessarily true.

Your argument against God being all-powerful does not use the same definition of “all powerful” that most religious people use. In Christianity, for example, all-powerful means “able to accomplish all possible actions.” Neither the logically impossible (creating a square circle) nor the metaphysically impossible (going against His nature) are possible actions in this context.

All-Knowing: Imagine the smallest particle of matter ( quark?). Now imagine the set of distances between this particular quark and all quarks in existence. Each set is unique to each particular quark and therefore must logically be stored within the quark itself to be considered ‘knowledge’, this is logically impossible. The same reasoning applies if we find something smaller than a quark. The same reasoning applies to particles within a god’s brain. Therefore, logically a god can not be all-knowing.

All-powerful: Can a god create something so big that the god can’t move it? Can a god create something so small that it vanishes from the god’s ‘senses’? Can a god create a square circle? Can an all-powerful god change the future? The past? It’s future or past? Can an all-powerful cause itself to permanently lose it’s ‘all-power’? Is it really logical to conclude that a god can be all powerful?