multiple Occam's razors

Well, obviously we should pick the simplest one :-).

Seriously: I wouldn't particularly expect there to be a single all-purpose slam dunk against all varieties of theism. Different varieties of theism are, well, very different. (Even within, say, protestant Christianity, one has the fundamentalists and the super-fuzzy liberals, and since they agree on scarcely any point of fact I wouldn't expect any single argument to be effective against both positions.)

ontology [...] epistemology

I'm pretty sure that around these parts the "epistemological" sort (minimize description / program rather than size of what it describes / produces) is much, much more widely held than then "ontological" sort.

I suppose you mean that the starting conditions are absent.

That's one reasonable way of looking at it, but if the best way we can find to compute morality-as-we-understand-it is to run a complete physical simulation of our universe then the outlook doesn't look good for the project of finding a simpler-than-naturalism explanation of our universe based on the idea that it's the creation of a supremely good being.