Putting it simply, your opinion about how good or bad something has been engineered has no real impact on whether or not that Creator exists. The equivalent is to say that I do not believe in the person that coded a line of script because I could make it better or because I can perceive flaws in it.
Regarding the rest, its is all supposition that you believe and I don't. I claim God as fact and you don't. Neither of us can prove the other wrong because we see the evidence and arrive at different conclusions. However, the fact that you can consider a particular object good or bad depending upon who made is is a bit intellectually dishonest. If it is crude, it is crude, whether by Creation or Evolution. Additionally your understanding of crude will change as your understanding of things change, so it only goes to show that we as humans constantly judge things with the shortest possible sight we can muster, while believing we have considered all that should be considered.
I Believe in God but I have no qualms with Science until it starts to posit unrealistic things like, Science and Christianity are at odds. The only Christians at odds with Science are the ones that have problems with their own Faith. And the only Scientists that have problems with Christians are the Pseudo Scientists.