the moral argument for God's existence is rendered logically invalid if morality depends on God's existence because it is circular reasoning. you can't say morals prove God, who therefore defines morals. better to say God and morals are both logically implied by something independant of either. for example, the forces of nature cause humans to be moral theists. if we mutate otherwise we become depressed or sociopathic, traits that tend to eliminate themselves from the gene pool.
Your concept of ex nihilo is rather strange if you are trying to be logical. If "God" is outside the equation, he's outside the equation. if he's a part of it, he's a part of it and it's not ex nihilo. the manufacturer is part of an automobile factory even if the relationship is tenuous. personally I don't find the big bang completely believable, but I do think eruptions of matter from dense energy sources could happen, just like a bomb explodes. for a star to explode is certainly no big stretch of the imagination.
life is a bizarrely complex mechanism compared to some others, but that doesn't mean it is in a totally different ballpark. if there's a mechanism by which all the necessary changes in DNA could have happened, it's logically sound to think it may indeed have done so. the fact is, it resembles a crystal growth pattern in many ways. it is certainly more complex by several orders of magnitude, but that doesn't rule out a fundamental connection. "it's a far cry from geometric patterns" sounds like you're denying the obvious fact that geometric patterns are exactly what it is.