Hey, I tend to agree with you that creationist arguments are generally uninformed. I believe wholeheartedly in the "old earth" scenario, and quite frankly although I find the evidence for macroevolution very dubious (as do many scientists), I do not necessarily think it's preposterous that we descendent from a common ancestor of the apes.
This, however, does not diminish my faith in God. The way I look at it is that if God gave us minds that are able to comprehend science, then we should look at what that science says and in turn, use that God enabled knowledge to see how we should interpret His word, in this case, creation.
For example, I believe that the Bible is not about the history of the earth, but about God and how we can have a relationship with Him and know Him. The true science of the Earth is far too complex (being from God and all) for even the most intelligent scientists to understand, so if God were to really give us a concrete scientific "play by play" of how things went down in creation, we wouldn't be able to understand it. And for what? The bottom line is the same in both cases: God created the universe.
I think we are meant to take the Genesis story metaphorically...the real truth of God's intricate design is too complicated, but we do need to know enough about creation to understand God's role in it. For example, and this is just a theory, I heard once that Adam and Eve could represent the stage where our ape-like ancestors found out, unlike any animals before them, that they could lie, steal, murder, covet, etc. If evolution is true, then at some point the animals that we descended from had to be able to have rational thoughts, which has led to humankind. This would be true whether or not God existed.
Anyways, I hope that makes sense...I think that the most vocal creationists do Christianity a great deal of harm, because their "science" is clearly misinformed. But that doesn't mean that God doesn't exist. I think God gave us enough info, in a metaphorical/poetic way, to understand His role in creation, and then moved on to more historical figures. I'm sure in heaven we will have a better understanding of how He did things. I think it is up to us to understand that whether the Bible is 100% literal or 100% metaphorical in the idea of creation, the same implications for our life can be drawn, which is the point of the Bible anyways: learning who God is and how we can have a relationship with Him.