With all due respect -- and I say that because I know from your posts you do value intellectual honesty -- you have no basis to say there is no "need" for God or an Intelligent Designer.
Simply because we can speculate on numerous possible theories and hypotheses which could be used to explain processes we have yet to more accurately observe and measure, none of which would require an omnipotent, omniscient super-being.
Sentence fragment. "Simply because [what you said afterwards]," then what? I'm not getting on your case for a typo. I'll assume the 'then what' is what follows in your next sentence.
To have a comprehensive theory of what reality is all about, the theory we have about reality requires that it can account for itself.
Well, let's be honest, we don't need a 'comprehensive' theory of 'reality' to be able to accurately describe basic elements of what can be objectively tested, observed and measured, as long as we have the technological tools which can help to minimise on the erroneous frailties of our own perceptions.
The type of "description" you reference here is merely relative description. Aside from the fact that any data provided by such "technological tools" are always subject to the frailties of our own perceptions (i.e. it doesn't matter how good the tool is if the tool itself, and the gathered data, are also subject to the frailties of perception), we already have examples of where such "technological tools" provide us with empirical data that lends to contradictory explanation. A powerful telescope is a great example:
On one hand, a telescope can provide us with data that lends to the extrapolation of an expanding universe from a single point in space; on the other hand, the fact that we observe galaxies in similar stages of development equidistant to our relative locality (i.e. to our right, we see galaxies at age
x and at distance
y, but we also see this if we look left, up, down, etc.) seems to suggest that
we are always at the center of the Universe. Empirical methods have no means of resolving empirical paradoxes, and it is only by deferring to abstract methods such as logic and mathematics that we can possibly resolve these paradoxes.
We can, and have, achieved a great deal in our short time of applying the scientific method, without needing to say we 'know everything'.
In a practical sense, of course. We needn't even consider cosmology to go about our daily life. But without knowing 'all that we can know,' we 1) can't assume God does or does not exist, and 2) can't assume that exploring the issue and possibly arriving at a conclusion won't yield practical value that is currently unknown to us.
Introducing gods into our hypotheses would be no different to introducing Harry Potter as an explanation for the origin of The Universe. Your philosophical gymnastics notwithstanding, I think we can safely proceed along the lines of ruling out our Universe having been created by a fictional character from a book, if you know what I mean.
First, I again remind you of the fundamental and crucial point that "philosophical gymnastics" are what allow the scientific method to work in the first place. Science is predicated upon empiricism which is a theory of knowledge acquisition. Empiricism defers to philosophy to say, "Okay, in order to explain 'objectively' in terms of empirical phenomena, we are going to control for the possible effects of observation by simply assuming that observation has no effects on physical phenomena." This is an entirely philosophical assumption, and it is empirically unfalsifiable. To empirically falsify this assumption would require that one collect empirical data of physical phenomena by means of observation in a universe totally void of observation (a contradiction). You must then ask yourself why you are willing to make what Hume calls "a complete departure from science" in order to explain it, but you are unwilling to make such a departure for anything else.
Second, Harry Potter by definition is a false analogy to an Intelligent Designer. Is is theoretically possible to empirically prove or falsify Harry Potter because Harry Potter falls within the scope of Empiricism. It is not theoretically possible to empirically prove or falsify an Intelligent Designer because an I.D. falls outside the scope of Empiricism by definition.
However: Your reply entirely misses the point about the requirement of a theory to explain theories in general.
Edit: The most intellectually dishonest point you make is even saying things like "philosophical gymnastics" to begin with. Absolutely all knowledge is predicated upon logic and Philosophy. Hearing you talk like this is like hearing BADdecker refer to the theories of science as "science fiction." A logical explanation, equal-to or greater in scope, trumps a scientific explanation 100% of the time, all the time, every time.